Originally Posted by m3larson
The roof rack seems like a good idea.. I am towing my M3 to California this weekend with my X5 4.8I. The X5 is going to drink gas and it's a pain in the but to tie the car down in a enclosed trailer is worth looking into the roof rack.
I used to carry around 5 wheels/tires on the roof of my E46M3 in a Thule basked on BMW bars. It worked well enough, with the main issue being the risk of dropping a tire on the car while loading.
4 tires also fit comfortably in the back seat on both the E9X and E46.