jackstar, it likely will reduce rental appeal etc a little, but as long as that is factored into your offer (and rent), then it shouldn't be a problem.
My IP (a house) has no garage or carport! It isn't a dump either - very attractive house! I would have had to pay more to buy it if it had a garage/carport though. It is in the outer Brisbane area (Narangba) and I get an excellent return (>5% gross).