Shouldn't matter. Alfa sell 4mm spacers specifically to adjust 35mm offset wheels for use on GTVs. I have the part number somewhere. So if the manufacturer says its OK....
Just to add, they're a lot cheaper too - only about £15 a corner.
Part number for the 4mm spacers is 60579027. In ePer they are described as a "BRAKE PLATE".
There's a picture here (SuperSports getting booted...)
showing how much hub lip is left with the spacer fitted.
Thanks Guys for all the advice. Decided to go the OE brake plate route. Just ordered them from Alfa dealer, cost £14.07 + vat each. Not in stock but should be in by weekend. Will post pics when fitted. Cheers
before everyone rushes out & fits these(I'm going to buy some) I thought I'd mention that most aftermarket wheels have about a 3mm chamfered inner edge that mounts the hub lip, many have to use a spigot ring to reduce the centre bore - these also have a chamfered edge, so with the 4mm spacer it won't leave much of a lip for the wheel to mount on.
Other std genuine Alfa wheels should be ok though as they don't usually have a chamfer.
Be careful, we don't want our wheels falling off.