I don't think which car you are driving matters very much. It's best if it's one you're familiar with, obviously.
It's how you are driving and whether you are paying attention, how dealing with any unexpected events. Even though it's a test and you're excited that you'll be so close (again!) to getting your license, the main thing is you're driving a real car during your test, and you must show you can really control that vehicle safely.
Focus on the requests from the instructor and work that into the environment you find your vehicle in at that moment. Like if he says ok cross this road we're approaching, and then parallel park behind that red truck up there? Well, be sure that you cross that road in a safe and legal manner. Don't get ahead of yourself. Is there a stop sign? Worry about the parallel park when you get there.
My first test was arranged so the driver would approach a divided boulevard just at the end of the test. One could actually see where the test had begun up ahead, so that was perhaps arranged as a distraction. The testing hour was middle of the afternoon and hardly any traffic. Naturally since the road I was about to drive across was divided, there were two stop signs. I didn't even notice the second one as I cruised through the mall area of the boulevard and across the other empty driving lane to finish up where the test had begun.
FAIL !! And it was really irritating to fail over something so stupid (and so vital to staying alive, I may hastily add). Anyway ever since then I still grimace when I prepare to cross a divided highway. You can bet I stop in the mall area for that second stop-sign now though. Every time I do that I think back to when I was so close to done, and then had to wait two weeks, then re-do all that other stuff on my second test, the parallel parking and Y turn, wow.
Of course on my second test it was a different route and some other hassle instead of a divided roadway, I think there was a roundabout and I remember having to go around a double-parked garbage truck, wondering what the heck the rules were when navigating past a rule-breaking vehicle...
and all the time totally obsessed over whether I was going to miss any stop signs. I think the guy told me "relax" a few times, I must have looked like a teenager on the very brink of insanity. Anyway I passed that second test.
Good luck!
Take the car you know best, and just keep your eyes open for extra stop signs
says my long-ago experience.