i think it sounds worse than it actually is... women age quicker mentally/ emotionally than guys so from that point of view i don't see why it couldn't work. the only thing you may have to look out for is either a. long-term relationship exes or b. he may want to move things along faster than you do because of life experience etc.. so don't ever feel pushed into anything. but i agree, 20 and 31 sounds a lot better. the car thing would bother me a bit too, but ask him about it and see what he says. good luck!
They called us a dead generation,
They told us that we wouldn't survive
They left us alone in the maelstrom
As you can see we're all clearly alive.