I agree with the suggestion to bring favorite tunes on a memory stick for testing, but be sure to format the memory stick as FAT32 (default format will not be read). Only MP3, MP4 and AAC files can be read.
If you decide to proceed, I recommend multiple test drives. Once you get serious, the store may let you have longer rides -- initial ride is likely only 15-20 minutes.
Also note -- At least in my area, the test drive is mostly on fairly straight highways. You may have to request a more interesting route -- you will want to test curving roads, and especially find some rough pavement. Bad roads will help you decide between air and coil suspensions and between 19 and 21 inch wheels (if you are undecided).
Test both types of seats. Do NOT assume the NextGen are better -- some people do not agree.
And if you are undecided about the sunroof, test with and without if you can. Different noise levels and different headroom.
Try to test a variety of motor/drive combos (70, 85, 90 D and non-D, P and not P). You may be happy spending less money on HP and have more to spend on nice options you want such as better sound or air suspension, etc.
The first ride will be mainly about first impressions, especially for a guest who does not drive. Acceleration performance is easy to demonstrate. But comfort, audio, handing, those take more time to experience and absorb.
Enjoy! It is a fun process!