Hello and welcome.
With any test drive I'd check every button. But the most common problem I am aware of is moonroof issues (sticking, not working), so if it has one of those, make sure you test it thoroughly. Holding the button down for a second or 2 and then letting go should cause it to open 3/4 of the way. Do the same again, it will open fully on its own. Then repeat to close it, it should go from full open to about 1/3 open, then fully closed on the 2nd push.
At least that was the only thing wrong with my 2005 XT when I bought it (32k), which was fixed free under warranty, and nothing has broken since (61k).
Have fun.