As stated if you fit in the car and can get in and out without issue then you've met the first test. After driving the Z if you like the feel of the car and the interior space you've passed test #2. Next up is the interior sound level ok for the roads you'll frequent the most if yes you just stepped past #3. #4, Will the car fit your life style?. Do you like the Z better than the other cars you have tested. If yes your at #5.
There is no #6. You should now be sitting at the dealership negotiating your price
PS I wouldn't worry about the 65 thing. The chief instructor for my local PCA region is 65. In the wet nobody can catch him on the track. That's where that skill thingy steps in.
Enjoy what ever you decide to go with.