I will admit that I only drove this because it was used on the Super License test on Special Stage Route 5 Wet. I believe this is a nice car to drive, I just haven't touched either one of mine.
The first one you get is for winning/completing the Sunday Cup on Beginner League. It sells for 3,387 credits. The second one is the S.S. model, obtain it by completing the FR Challenge on Amateur League. This ones sells for 125,000 credits, and it can't be bought. Only chance to have it is here, don't sell.
I have personally never sold any cars I have bought and/or won. There is plenty of room in the garage for all the cars in the game, and I want to complete the game and have all the cars. That way I can comment from experience later about any of the cars in GT3. There really isn't a point in selling a car in GT3, I don't think...