I don’t get the comments about towing behind a car. My ASW-19 & 20 both lift the tail dolly wheel off the ground when I tow them.

There is a fairly common tow bar system (Initially offered by DG, I believe) which uses a long square tube with a round tube at the glider end welded at 90 degrees. This tube slips into a round tube receptacle mounted at the tail dolly caster. The opposite end of the long tube has a tow ball hitch. With this system, the glider is towed with the tail dolly wheel on the ground. A pneumatic tire can wear out or go flat if you have to tow long distances or over rough terrain. A solid tire is a better choice, provided it isn't TOO hard. You should try to find a solid tire that is similar in "softness" to a pneumatic tire to avoid vibration and shock.