[Scott Douglas]

My brother and son both have them. I think they both have car jackers, but not sure.
I noticed when using the ones at my son's house that the 'pebbles' in the floor paint make it hard to get the car moving at times, but once moving it isn't all that bad. I think the bigger the diameter of the caster wheels the easier it will be to move. Both use the kind you slip around the wheel and then jack it to bring the wheel off the ground.
I think this is the kind of thing where you get what you pay for as far as quality goes. My brother has a nice rack that the dollies sit in when not being used, which is nice as it keeps them available and ready for quick use. I don't think my son's ever leave the car they're presently under as there's no need for them to be used elsewhere.