In reply to wbo2:
I agree although only if it fits in your car.
However two pads provides a lot more flexibility. I carry one big (Petzl Cirro) and one medium (Ocun Moonwalk) everywhere (or more). Two medium size pads is also ok for some stuff.
If the car permits, getting one good large pad and one much cheaper medium pad is a good solution. The medium pad could be bought second hand; if it's gone a bit soft you can just use it to pad out parts of problems before you get too high, with the bigger pad used for those.
But if the OP isn't yet sure how keen they are I would just start off with one medium pad and be sensible about choosing problems (straight up, not very steep).
Post edited at 08:43