I like the ramps but it can be hard to get the front wheels of RWD cars to climb them, if you have a smooth concrete floor. They want to slide along the concrete. On textured concrete or asphalt it's less of a problem. Of course, you should chock the wheels that are on the ground in both directions.

I put stands under the car as a safety even when I use ramps, just in case a ramp decides to fold up on me. (I live in an earthquake zone.) Don't forget to take the stands out from under the car before you back the car off the ramp, though...it's really embarrassing if you don't.