I recently got a B/W 97 GTS and joined VCA. So, hello everyone 
After driving for the first few days I loved the car, but did not like the OEM head unit. It only played CDs - and since it is 2016 already I felt it needed an upgrade.
Subjectively I also think the produced sound from the OEM head unit and OEM amp, is too narrow and makes music sound thin.
After doing my upgrade I decided to document it here.
I did not want to spend a lot of money on this upgrade and bought a head unit on black Friday (KD-X31MBS).
This unit had exactly what I wanted: aux/usb/bluetooth input, and no more CDs...
Ofcourse I was unaware that this head unit produces speaker level output and does not work (well) with the OEM amp.
If speaker level output is used with the OEM amp there will be: a hiss at low volumes, loud pops when starting the car, narrow volume control (low volume sounds extremely loud already).
Therefore I also replaced my amplifier, while keeping the look original and reusing the OEM housing.
Note: If your goal is to only upgrade the head unit. Make sure the head unit you purchase, has line level outputs for all 4 channels.
Usually this means it will have 4 RCA outputs.
An additional restriction I made for myself was to keep the original wiring and connectors. Asked around for a harness but one does not exist.
Got qouted some outragous numbers, without knowing whether they would splice the wiring or not.
I ended up getting a used Gen2 Radio + Amplifier and extracting the connectors from there.
Amplifier upgrade
For the amp upgrade I bought a used Gen2 AMP (did not want to part out my own).
The amp that I wanted was the ALPINE MRV-F300, it is rated at 300W RMS and should be enough to drive (and overdrive) the stock 50W speakers in the car.
The MRV-F300 is smaller than the stock amp and I made it fit by drilling into the OEM housing.
Additionally it has auto power on for speaker level input, and allowed me to separate the ground of all channels by dropping the remote wire to the amp.
[Original OEM viper amp main board with connectors removed.]
To remove the 8pin connectors from the original main board, I used a rework station with an infra-red soldering light. This can also be done with a heat-gun.
[The new main board installed]
I used a protoboard to hold the original connectors in place. The wire terminals are there to make it easier to re-configure the inputs in case I ever put the original head unit back in.
[Reseated connectors from the side]
I decided not to bother with the fuse. Hard to desolder and would need some fat wires to connect to the new board.
[The MRV-F300 installed in original housing.]
Looks stock
Head unit upgrade
To put in a new head unit the dashboard needs to be taken off.
Here are the points that need to be pulled at to take the panel off.
Start with pulling the ashtray out, this will give more leverage to pull the dashboard panel off.
Interesting facts about the connector for the head unit.
[BAT] Battery - 12V power which is always on as long as the battery is connected.
[GND] Ground.
[ACC] Accessory - Sends a +12V signal, when the key is turned to ACC mode, disconnected during ignition.
[PARK] Parking mode - (Unused with aftermarket HU) Sends a +12V signal when car lights are turned on. Even if engine is off and no key is present.
[AVC] Auto volume control - (Unused with aftermarket HU) (Unfortunately I did not measure the signal that is produced here. If anyone knows, please share.)
[ILL] Illumination - allows headunit to determine when to dim the display. +12V when lights are on.
[ANT] Power antennae - Allows the antennae amplifier to be turned on and off when the head unit is on. Should be wired to [Remote out of HU].
The above explanation should help you wire the vipers connector to the new HU.
Here is the project enclosure I built: I added wire terminals onto the protoboard so I could rewire it later if needed.
I admit it is not the best looking project enclosure, but it will not be visible because it will be hidden behind the installed head unit.
The connection diagram will be different based on the HU, but should match to the pins listed above. The ANT will need to be connected to the remote out of the head unit.
One hacky modification I did: is merge ACC and PARK, this allows me to keep the HU running uninterrupted when I turn the engine off. This was important for me because my HU drops the BT connection when its ACC is briefly interrupted.
There is still the issue that BT gets interrupted when starting the engine. (Might look at improving this later.)
Here it is installed.
After driving for the first few days I loved the car, but did not like the OEM head unit. It only played CDs - and since it is 2016 already I felt it needed an upgrade.
Subjectively I also think the produced sound from the OEM head unit and OEM amp, is too narrow and makes music sound thin.
After doing my upgrade I decided to document it here.
I did not want to spend a lot of money on this upgrade and bought a head unit on black Friday (KD-X31MBS).
This unit had exactly what I wanted: aux/usb/bluetooth input, and no more CDs...
Ofcourse I was unaware that this head unit produces speaker level output and does not work (well) with the OEM amp.
If speaker level output is used with the OEM amp there will be: a hiss at low volumes, loud pops when starting the car, narrow volume control (low volume sounds extremely loud already).
Therefore I also replaced my amplifier, while keeping the look original and reusing the OEM housing.
Note: If your goal is to only upgrade the head unit. Make sure the head unit you purchase, has line level outputs for all 4 channels.
Usually this means it will have 4 RCA outputs.
An additional restriction I made for myself was to keep the original wiring and connectors. Asked around for a harness but one does not exist.
Got qouted some outragous numbers, without knowing whether they would splice the wiring or not.
I ended up getting a used Gen2 Radio + Amplifier and extracting the connectors from there.
You must be registered for see images
Amplifier upgrade
For the amp upgrade I bought a used Gen2 AMP (did not want to part out my own).
The amp that I wanted was the ALPINE MRV-F300, it is rated at 300W RMS and should be enough to drive (and overdrive) the stock 50W speakers in the car.
The MRV-F300 is smaller than the stock amp and I made it fit by drilling into the OEM housing.
Additionally it has auto power on for speaker level input, and allowed me to separate the ground of all channels by dropping the remote wire to the amp.
You must be registered for see images
[Original OEM viper amp main board with connectors removed.]
To remove the 8pin connectors from the original main board, I used a rework station with an infra-red soldering light. This can also be done with a heat-gun.
You must be registered for see images
You must be registered for see images
[The new main board installed]
I used a protoboard to hold the original connectors in place. The wire terminals are there to make it easier to re-configure the inputs in case I ever put the original head unit back in.
You must be registered for see images
[Reseated connectors from the side]
I decided not to bother with the fuse. Hard to desolder and would need some fat wires to connect to the new board.
You must be registered for see images
[The MRV-F300 installed in original housing.]
Looks stock
Head unit upgrade
To put in a new head unit the dashboard needs to be taken off.
Here are the points that need to be pulled at to take the panel off.
Start with pulling the ashtray out, this will give more leverage to pull the dashboard panel off.
You must be registered for see images
You must be registered for see images
Interesting facts about the connector for the head unit.
[BAT] Battery - 12V power which is always on as long as the battery is connected.
[GND] Ground.
[ACC] Accessory - Sends a +12V signal, when the key is turned to ACC mode, disconnected during ignition.
[PARK] Parking mode - (Unused with aftermarket HU) Sends a +12V signal when car lights are turned on. Even if engine is off and no key is present.
[AVC] Auto volume control - (Unused with aftermarket HU) (Unfortunately I did not measure the signal that is produced here. If anyone knows, please share.)
[ILL] Illumination - allows headunit to determine when to dim the display. +12V when lights are on.
[ANT] Power antennae - Allows the antennae amplifier to be turned on and off when the head unit is on. Should be wired to [Remote out of HU].
The above explanation should help you wire the vipers connector to the new HU.
Here is the project enclosure I built: I added wire terminals onto the protoboard so I could rewire it later if needed.
You must be registered for see images
You must be registered for see images
You must be registered for see images
I admit it is not the best looking project enclosure, but it will not be visible because it will be hidden behind the installed head unit.
The connection diagram will be different based on the HU, but should match to the pins listed above. The ANT will need to be connected to the remote out of the head unit.
One hacky modification I did: is merge ACC and PARK, this allows me to keep the HU running uninterrupted when I turn the engine off. This was important for me because my HU drops the BT connection when its ACC is briefly interrupted.
There is still the issue that BT gets interrupted when starting the engine. (Might look at improving this later.)
Here it is installed.
You must be registered for see images
Great write up, you are like fish in water with all these spaghetti of wires. welcome to the club and enjoy your new viper. 
