Me neither.. I kind of understand how everything works but just like to compare and race stock cars for some reason .. I also tend to sell tuned cars in GT games if I don't need them for some events anymore.
Edit: But also found out that many GT 'tuners' don't actually have a clue what are they doing. Many times fixed sports suspensions are better than their brilliant setup.. And you can always play with brakes, downforce etc yourself and obviously gear ratios for individual tracks..
Edit2: Countach killed WS race with weighy reduction 2 and sports ECU.. Thanks anyways.. Now I need another not touched Countach