I suppose the cost is the cost either way. I was thinking more along the lines of keeping the car looking stock while also going fast. I think there's a few guys that have been experimenting with squeezing the most out of what the cars came with without going and buying a bunch of random parts.
The questions was never so much to make it look stock. it was to keep it stock or go to town. If I start modding, i wont try to hide the upgrades.