towing with dolly ...

Idling the car in nuetral for the 30 miles will do the trick, the pump is active and circulating fluid and you have airflow to cool the radiator.
Works with manual trannies, too.

Tow dollies are like anything else, if you use them enough, make a few minor mistakes, you learn the inns and outs.
After some time, some people can use them as if it's 2nd nature.

I look at it this way, th U.S. D.O.T. hasn't illegalized them, yet, so they must be alright in COMPETENT hands.

I wouldn't sell mine unless it was the very LAST way to eat. Have had it for 15 years, backed up with it, towed backwards (NOT recommended!) with it, even towed 1-ton duallies with it. It's been a very reliable and simple TOOL.

It also falls, according to Federal D.O.T. Mandates, in a "No Brakes Required" category, since it technically is rated under 3500 pounds.
It would be better with brakes, though. :)

One thing to do is have as much weight ON the dolly as possible.
With mine, if the towed vehicle has no engine, the towed vehicle will sometimes want to "whip" and dance around, pendulating, if you will.
Creepy feeling, especially with a 1/2 ton and nothing for weight in the bed.

Mark.