For a number of reasons I wouldn't.
If you go wider you'll have to run lower profile tyres, or offset the wheels further out. Don't know about Austria, but it's not permissible to have wheels/tyres protruding beyond the body line (wings) in the UK. Increasing wheel offset puts a lot of extra strain on suspension components.
Sidewall flex is a part of the suspension.
Plus you'll mess up the handling...
when you get your 4/4
