I know this is just me dreaming, but I think it would be awesome if we had full control over the parts we put into our cars. Like putting some 270 degree intake cams and 280 degree exhaust cams. Being able to pick the exact turbo we want GT2530, GT2835, GT3240, power vs lag. Having to worry about bigger radiators, oil coolers, intercoolers, fuel pumps, injectors, engine strength, boost levels, the tuning of the computer, etc. I know this isn't what Gran Turismo is set out to do, but I sure would like it! Are there any games out like this?