It would be Paul Thanks'
edit, actually I'm not sure.
It if was for example Chris it would be Chris' car and not Chris's
wouldn't that be if his name was Paul thanks instead of Paul thank?
I'm embarrassed to post on a forum where this is a question!
It would be Paul Thanks'
edit, pretty sure at least.
If it was for example Chris it would be Chris' car and not Chris's
Indeed. Otherwise Paul Thank is car.