It took me about a month to get my wife onboard with the idea of buying a Viper. We preferred the original styling, so I limited my search to Gen1 and Gen2 Vipers. During this time, I did some fairly in depth research to determine the changes and improvements made for each model year. This helped us decide that I ought to limit the search to the 2001 and 2002 model years. Anti-lock brakes and powder coated brake lines were the deciding factors for me. Learning that Viper front brakes tended to lock up first, I decided that anti-lock brakes was an important feature. Having dealt with the danger and expense of replacing rusting brake lines on my '98 Durango, the fact that Dodge switched to powder coated brake lines the same year that they added anti-lock brakes sealed the decision for me. Narrowing the search to just two years necessitated widening my search to nationwide.
My wife's preference was for a Sapphire Blue RT/10 with Cognac interior, so a nationwide search was essential to turn up a small selection of cars--typical search results was 2 - 4 cars. I checked up to 10 sites daily. Most sellers advertise on multiple, but I didn't want to miss the one car that might be posted to just one site. So, I checked Cars.com, Autotrader.com, Carfax.com, Cargurus.com, Carsforsale.com, ISeeCars.com, TrueCars.com, Hemmings.com, DupontRegistry.com, ClassicCars.com and Ebay.com. There is also Auto.com now. Cars.com is my favorite site, since they provide the best set of info up front. You are provided a Picture, Year, Make, Model, subModel, Price, Mileage, Seller, Seller Phone, Distance from Seller, Exterior Color, Interior Color. Autotrader.com and Cargurus.com provide all of the above except interior color, thus requiring an extra step to find it. Carfax.com and Carsforsale.com also leave off the Seller Phone.
Checking 10 sites daily is quite easy to do. You just open a separate tab for each site and click the refresh icon for each tab each day or evening before doing your check. BTW, I never thought to check Craig's List, but several have found decently priced Vipers on Craig's list. Also, there is a Facebook group (Dodge Viper Owners and All Viper Clubs Member's Site) that has a page for posting up Viper and Viper parts and accessories for sale. Of course, the Viper Owners Association and Viper Club of America each have a Facebook group as well. From time to time, you will see For Sale posts there too. Good luck! I ended up buying both of our Vipers at Ebay.com. Not the way I thought things would play out, because when you bid or select "buy it now", you commit to making the purchase. However, Ebay makes it easy, because if the item doesn't match the description, you are off the hook. Of all the sites, I think more Vipers on Ebay are single listed (just there) than any other site. Two Vipers? Yes, originally we struggled to decide which body style we liked more. I made the silly suggestion that we buy one of each. Over time, I got serious about the idea and proceeded to convince my wife that a his and hers was a good plan. Once she was onboard, I set my sites on an ACR. No regrets. We love both. We found her RT/10 in Carmel, CA and my ACR in Texas. Lemon Squad handled the PPI well, and we used United Routes for shipping.