Car dolly's what to look for?

Gundog wrote:
I want to get a tow dolly what features am I looking for? What tie down type? what design?

I do not want to break the bank I have plenty of room to store it I already own 2 16' car hauler trailers one enclosed and one open but don't want to deal with a trailer that size.

I don't want to trade cars mine can't be towed 4 down a 2008 Mazda 6 auto FWD.

I have the ability to repack or replace the bearings and races if needed. There are many on our local CL used. I am setup for electric brakes on our MH. What do I look for?

Eventually I will get a different car that can be towed 4 down I have a tow bar that I got with our coach.