getting the oil changed etc... you could go to renault and theyd do it for a ridiculous price... if you want the oil done, brakes + air filter then id go to a local garage that would do it much cheaper...
If youre looking to buy a mint williams I would imagine you want one with low-ish mileage, ie: under 72k which is when its cam belt wants changing. Mine is due for this in another 6 thousand miles and there aint no way im taking it to renault.
The way i thought about it was that when was the last time a renault mechanic would have seen a williams.. probably never, unless hed been there for in excess of 6 years. Im going to get mine changed by hill power, at least nick hill is used to dealing with these cars day in day out, plus hes a bit cheaper...
Renault cam belt change = 280 quid...