95 Carrera Repair Input

[Ronzi]

Good grief.
It's guys like this that give regular maintenance a bad name.

The usual places for oil leaks on air-cooled 911s are the oil return tubes and the cam covers, neither of which are very expensive to fix. You gotta figure at least $500, though.

[Perfectlap]

I've long wondered if the whole "change your X miles or every X months" is not just a way of selling more oil product. Particularly with syntetic oils and cars that are barely driven like your friend's 10 year old Carrera.
The filter is a different story. Anyone who has ever swapped out an air filter can see that these things get filthy.