The cars for this part of the experience were lined up in this order:
Z4
330i
Z4 M
M5
M6
760Li

All of them were pre-setup for us and given to us with engines running (M5 and M6 were already pre-programmed with the shortest timing for shifting, P500 mode, etc). We were asked not to turn off the engines when changing cars and we drove them to one of the circuits.
Once there and lined up, we started the performance driving, all together, sort-of racing each other around the circuit and keeping the shifting up to 2nd gear only (small circuit and a lot of pep).
The instructor on the side of the circuit kept us on radio and would tell the red Z4 (the one in front) when it was time to turn in. First stop you would change drivers, and allow a few secs for adjusting seat, steering, etc. Second stop was for changing cars. We started with the first one, the red Z4, so for us the next one was the 760Li, and so on (the drivers of the last car would move up until they reached the first car).

The Z4 M compares to the Z4 obviously except that since it had a manual tranny, it was a lot more involving than the automatic. I got to do a nice tire burning and spinning with the M at take off which I loved. Both Z4 and Z4 M (with open tops) had similar handling but the M obviously had a lot more power. You could feel it from the very moment you stepped on the gas pedal.

Not sure why the lining of cars was that way, but the Z4 M (at least myself driving it) I would catch up to the 330i almost at all times obviously due to the overwhelming power of the M in contrast to the 330i and had to idle and break a bit too much on it...

The M5 was no surprise to me since I had already driven it before, same excitement, never gets old. The M6, well, that was my favorite, you could feel a little bit more sportiness than in the M5 and the handling was just as rewarding as the 6er, with a dose of steroids of course, and the noticeable extra amount of power (you can easily tell -and feel- there's an extra 140 HPs there). You can also notice the interior of the M6 is a notch above the M5, more in line with the 6 Series, as it should be.
M5 and M6 back to back very comparable and a nice pair to have in your garage if you are into M cars. Both beautiful to look at, they look great together.

The 760Li, ahhh, well what can I say about the flagship of BMW. Superb! This is a very HEAVY yacht. Not one to be used on these circuits obviously, but one for pleasant drives around town and long trips. Very very plush and comfortable. Tons of power to spare, filled with techno gadgets but handling just like a big boat (when compared to the other cars in line). It is a big car and the V12 feels appropriate for such a vehicle.
The 7 Series and M6 also look good together!! and the interior's are not as far apart as, say, 6 Series and 3 Series.
You can tell the leather of the 7 like no other one from BMW, everything a bit more meticulously fitted and the materials used felt first class.

The 330i felt a bit underpowered and heavy, lacking the good handling the others had on the circuit. It is a nice small car except it was eclipsed here by their bigger and more expensive siblings.

Overall, body built, fit and finish all very good, the 3er interior controls felt a bit plasticky, the 760Li the most luxurious and quiet obviously, the M5 and M6 built for performance inside and out almost intoxicating when squeezing that gas pedal and hearing the roars revving up and down.
The Z4s had a lack of that typical German 'thunk' when you closed those heavy and thick doors (maybe they are lighter than what they appeared to be) it was more like a 'clank'. The flaming surfacing is something really enjoyable from the inside, it feels like the car 'flows' as you see this long and beautiful hood. A fun car to have for weekends if you ask me; not my choice for every day.
All in all, each car felt appropriate for their own category.