My car has 21k miles on it and runs much better than it did when it had only 5k miles on it. Although my new engine only has about 11k on it. Remember 04's have weak rods and are prone to breaking especially if you increase your power by even 25 to 30 hp. Call Chuck Tator for an ear full on how many 04's he has had in his shop due to blown engines from failed rods. Mine was one of them.
Also, when I bought my Viper it only had 1012 miles on it. The previous owner did a 180 on the L.I.E. w/ his wife in the car and scared the ****** out of his wife. She made him sell the car the same week. Traded it in for a Benz CL63. That could also be the case here.
And this Viper u r considering looks practically stock all the way down to the air filters. That is a good sign. His roll bars look stock, which means this car shuold not have been tracked. It does look like he modified the tires, those tires seem lower profile than stock. To me, he seems to have driven the car for show and not for the performance. This car might have been babied. But you will only know when u see it close up and personal.
Just my .02