[Graham]

I would like to know what a fender is ?
if it is arches, as a google search result suggest, then I think 68mm is way over width for 1/32 car, I don't know of many cars that are 2176mm wide ... a Greenwood Corvette is pushing 2083mm at the rear which scales down to 65.1mm.

According to the CSCRA rules 68mm is permissible for the body width of Can Am cars of the era, I have measured a Carrera Porsche 917/30 which is 67.5mm body width which I know is basically accepted as being in scale for these type of cars. Fenders in my mind are the front and rear body mouldings or in old fashion terms the “ bumper front and rear impact protection mouldings”
The body width measurement is normally made across the widest parts of the body, chassis, wheels and tyres, wheel arches can be accepted outside the limits if can be shown to have been wider on the real car.