I think I need to get towed here. How do I do it?

In the Eastern Wasteland you have a new mechanic, the guy from the "Resistence."

You get towed the same way as in the other Wasteland. You just click on your radio phone thing, and get towed. It's in your inventory. Of course, you probably need to have talked to the mechanic, I don't know why you'd drive without meeting your mechanic in the first place.

I don't think you can unless you just got to Resistance Base for the first time, knew which door went to the garage and took off. Otherwise, the mechanic blocks your path into Subway Town and gives you his little speech including the part about towing.