Towing Issues: tow dolly, auto trader magazine, drive wheels

Question
when using the tow dolly, miles are registering on your car, correct?  whats the cheapeast way to get a one car tow trailor for towing most cars?

Answer
Ok  I am understanding that you are asking about the type of dollie where the vehicle has one end of it on the trailer and one end on the ground.

Now you are SUPPOSED TO have the drive wheels of the car on the tow dolly to prevent transmission damage from possibly happening.  

The odometer will not register mileage if the drive wheels are not turning. Most of the cars use the transmission as the point of reading for mileage. Some use an actual drive wheel for read point.  
Now as to getting a tow dolly or actual trailer that can handle a car.  You should have several local trailer dealers who can sell you a trailer or tow dolly.
Then you also have the local  newspaper, Auto Trader magazine, or even EBAY..

I hope this is the information you were looking for