Here is my write-up from installing this product about two years ago. I hope this helps...
For the whole thread click on:
http://forums.viperclub.org/srt10-srt10-coupe-discussions/588715-cruise-control-works-great.html
Finally finished the job and it actually works. It was a lot more work than I thought it would be to put it in but it does work quite well. On long trips I will definitely be glad I installed it.
Two clicks on the transmitter to set the speed, one more click to speed up or slow down once on cruise. Tap the break and it shuts off.
It took me 10-12 hours to install this item. I am not a mechanic, but I am also not too bad with tools and wire splicing/soldering. The main challenge is the directions, also one of the brackets did not fit and had to be drilled out in order to mount it on the factory studs on the interior transmission tunnel. Also, the bracket to hold the transmitter does not fit/clip on the lower dash panel like the picture shows you. I simply used the supplied velcro and did not use the clip. Now that I've been through one install I could probably install the kit in about 2-3 hours.
Here are some tips for those who buy the kit and will install it themselves:
Taking the inner fender well off:
1)Gently unscrew the plastic fender well thumbscrew retainers. Don't force them since they are fairly soft plastic
2)The two retainers that hold the top piece of the fender well have philips head screws, but they screw into molleys. You have to hold the outside rim of the molley so it does not turn, then unscrew with the philips head and the screw will come out. Then genlty pull out the molley
3)The plastic cap looking things that hold the mud flap and rear inner fender well in place are plastic plugs that need to be gently pryed out. The piece that is left(it is larger than the head of the plug) is a large molley which needs to be gently pulled/pryed out once the plug is fully removed.
4)Take all the screws off the side sill(Top and bottom). This will allow you to gently pull the side sill/fender away from the rear inner fender well and remove it.
5)Be carefull not to scratch the painted lip on the fender since the inner fender well has some sharp clips attached to it for the mounting screws. I used masking tape on the fender lip to prevent it from getting scratched.
Feeding the cable and harness through the gromet:
1)The instructions say you can slip it through the gromet, but I just did not see how. I drilled a hole in the rubber gromet above the factory harness and the cable and harness went right through to the foot box. I then used silcon sealent to make sure no moisture would get through.
Connecting the two wires to the hot and cold brake wires:
1)I would get on my back with you're head looking under the dash. You will see a switch attched to the front of the break pedal assembly. Gently rotate the white switch counter clockwise and gently pull it away from the bracket and it should pop right out when the tabs align with the holes in the bracket. Once out, you can drop down that wire harness and splice right into the two wires.
Hooking up the harness to the 12V accessory wire:
1)You need to take off the lower dash panel. Unscrew the two screws at the bottom of the panel. There are four aluminim clips mounted on the top of that panel and one on the side near the center console. Gently pull the top of the panel down from right above the pedal adjustment switch. You should be able to get a good grip on it there. Once you see how the clips pop out, pull the rest of the top clips out, then gently pull the panel so the side clip pops out from the center console. If you disconnect the harness for the power pedal adjustments the whole lower dash panel can be removed. Actually this would be one of the first steps I would do, it would make installing the cable and everything else easier.
2)I disconnected the harness from the bottom of the steering column. There is a red plastic harness lock that needs to be slided/pushed to the other side before it will let you remove the harness plug. Once removed, you will see there are two fat pink/violet wires and two thinner wires with blue tracers. The two pink wires are the hot wires, one is powered all the time, the other is powered when the key is in the accessory position. That is the one you want. That pink wire was in the middle of the plug while the other pink wire was on the end. Anyway it is easy to check with a tester when it is hot or not.
Hope this eases the install process of the next buyer...
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Current Ride: 2009 Jaguar XF Supercharged
Previous Cars: Vipers - 2006 Viper Coupe - 2001 GTS
Corvettes - 68 Vert, 82 Coupe, 96 Coupe, 99 Coupe
I used the strong velco it came with to mount the control to the right side of the steering wheel. It took me most of a day to install, taking my time, and finding wires in different places than the instructions showed, that way I could hide everything as much as possible. 
Maybe I will cough up the money and get this thing installed.
