Yeah - I have the SUV for that too - but I live alone and if I go - he goes! So if he does not go in the Z4 - neither do I! When I bought the seat over I did get a harness for him - mostly in case he sees a deer and decides to run after it while we are going 80......
Here is one of my favorites of him my GF took years ago when he was a young buck and my father and I were quail hunting with him. His head comes up to about the door handle, so not sure how this will work.......