I was in Bishop Ca. last week, passing a gas station I noticed those two. A quick U-turn going in and got in line. Speaking briefly with one of the drivers he said (with a heavy German accent) that this is the most powerful new X3, the M. At the time I new only of the upcoming M40 so I tried to correct him but he repeated that this is an M and pointed at the four exhaust pipes.
About twenty minutes earlier I was driving the wonderful 168 south of Bishop when I saw two cars in front of me something looking like a BMW test car. Eventually he took off and I promised my wife I will not try to catch him (like I had a chance). Few minutes later I saw him standing facing the opposite direction ready to enjoy this road again. I stopped and when I got my phone to take a quick picture he asked me to let him duck so he is not in the picture. The sedan is an M5 (again according to the driver).
About the tires -- can't see the size, but from the original files I can clearly see that these a Bridgestones, I can also identify the print "TENZA" on one tire, so it's got to be Bridgestoe Potenza, again no size information.
Sorry for the long shpill, it was fun seeing the future generation of my car being tested.
See more X3M info at
http://www.bimmerpost.com/category/x3m/
