I say for each $1000 spent on go spend about $250-500 on show, but if its a car like the 350Z i say that ratio can be stretched to 5000/500 in favor of go because the car aleady looks tight as hell from factory but an srt-4 can whoop its ass. but for a car like the EVO or STi it should be about $1000/$750 cause they are fast as shit but could look a little more sleek and clean, but thatts if you wanna make it a show car.