A: This ramp is for the back of an SUV. The ramp for a car door would be a free standing pet ramp.
A: I bought mine 5 yrs.ago for my German Shepherd with bad hips,so I'm not sure.It's well built tho.
A: No, I would be slippery on deck stairs.
A: No, The ramp could slide when your pet is using it as there is no way to secure it.