Yep as richierich said really, bottom's of the front wing's are the most obvious place to look, sills where they've been jacked up and arches, especially if it's early car with plastic arch trims. Grommets in the floor pans are really common for them to go, front suspension turrets go around the seams, I think that's covered the worst bits! Hopefully that hasn't scared you off! The good thing is though that mk3's are still very easy to get bits for, decent fitting pattern front wings can be bought for around £30 and replacement sills about £20 and there's still plenty of very cheap 2nd hand st