Has anybody managed to fit 18" wheels on their scooby without having to modify the arches? If so what width are they and what offset do i need.
What size tyres do i use?
P.S I don`t want them to rub if i`ve got 2 people in the back.

 

7.5 x 18 is the max with 50mm offset (i think this is what the 18" P1 wheels are too - check with Prodrive), but you need to be very careful with your choice of tyre. Even the same profile across different manufacturers can cause problems.
Tried and tested is Pirelli 225/35/18 P Zero or 215/35/18 P7000 with no issues.

Sunil