Overheating issue

I'm looking for a little help on a nagging problem with my gf's BMW 325xi. It is an automatic and has about 90,000miles on it and we live in Phoenix to give you an idea of the ambient temperature. To make a long story short the reservoir tank was cracked and caused the car to overheat so I replaced that but the car still experienced overheating. I next replaced the water pump, thermostat, fan clutch, and belts. I knew the fan clutch to be bad for sure and I figured it was time for the other two. I have a scan gauge 2 hooked up to the car and have been seeing temperatures that fluctuate drastically. I will see temperature of around 200F once he car gets up to temperature and then after some stop and go driving it will go up to 220F-225F, on the freeway the temperature seems to stabilize around 215F. Obviously the dash gauge doesn't move but these seem a little high and volatile to me as my Mini Cooper will get up to temperature at 202F and will sit there like a rock. Kinda curious if anyone else has taken temperature readings and see any fluctuations that that or if it generally is constant. Yesterday she took the car out and the needle actually started to move off center. She turned off the a/c and the gauge went quickly back to center. I have to take this thing on a long roadtrip in a couple of weeks and would really like to have this problem fixed. I'm wondering if I got a faulty part, I'm open to any help and suggestions.
Thanks

You probably have an air bubble trapped in the system. Try bleeding it again, with the front end of the car slightly elevated....(make sure the heater & blower are on)

When I completed the work I had the cooling system flushed and bled at a garage as I was concerned about air pockets, but nothing says they did it right so I'll give that a try.

Yes, I say bleed the system again.

Sometimes air can still be trapped.

Best

Joe

I mentioned that my Mini will run a steady 202F when I read from the Scan Gauge II, does anyone have a typical temperature that they usually run at and is it a constant? Just trying to get a baseline number that this system should be running at. thanks.