I towed our PT Cruiser on a dolly from Montana to Georgia and back. No problems. None of the horror stories often stated on these forums occurred. NONE! I bought a cover for the front of the PT to protect it. The cover worked quite well. It wasn't perfect, but it did the job for which it was designed. Such covers are available for nearly any vehicle. Google it.
Dolly towing is perfect for front wheel drive vehicles. Every 4X4 or AWD vehicle I have ever owned (Jeep, Ford, Chevy, AMC Eagle, Subaru) absolutely forbids towing on a dolly unless the rear driveshaft is disconnected or removed.
In fact, some vehicles are not towable at all without some form of modification. I used to tow a Datsun diesel two wheel drive pickup; I had to get under it and disconnect the driveshaft to avoid transmission damage. It took about 5 minutes.
What does the Colorado Owners Manual say about towing?