I just towed a 7 X 16 foot trailer with 3 motorcycles and do not know why so many of you owners rave about their X5's. I have a 2006 4.4 and I was not at all impressed with its towing. I towed the trailer form New Orleans, LA to Panama City, FL and ever little incline caused my X5 to down shift into passing gear and reved up the RPS to 4500 and higher. Sounded like it was going to explode. You definitely can not tow with cruise control unless you are on a level roadway . I had to actually get a running start and then slow my pace to prevent the tremendous down shift. We are not talking about any big hills in Louisiana or Florida. My 2003 Volvo XC90 T6 towed better. I suppose it had a different set up in the rear end of perhaps the 4 speed transmission had somethijng to do with it. How could you possible tow a 20' car trailer with that Viper?