I don't think that these lifts would support the weight of a car being driven over it, especialy the non commercial grade lifts.
kemo
Not sure but I think what he meant was having a couple of thick wood planks in order to lift the car a few inches. (to get ground clearance for the steel bike lift)
I'm guessing that you have 3 vehicles? Is one of them a truck or offroad vehicle that you could just park over the lift? I don't want to sound insulting, it's just that sometimes the simplest answer gets overlooked.
However, parking a vehicle over a lift is not as cool as having it built in or stored overhead.
In the US if you have a pit in your garage you are asking for trouble when you go to sell the property. Just make sure, you may want to fill it in, if you ever sell the house.