First of all, why would the guy from the rim shop bulls.hit you? The bigger the rims he sells you, the more expensive the rims and tyres are, and the more comission he would earn.
If he says they won't fit, they won't. Some cars just do not have enough room in the wheel wells for rims that big.. I know that without changing my front struts for coilovers I can't fit rims any bigger than 18 inch to my car. Without changing the spindles and fenders, I wouldn't be able to fit anything bigger than 20 inches.
