Great news! I now have two buyers lined up to buy my Audi from me so I can buy a 944.

Question though: how do you deal with having two buyers who want to look at the car on the same day? The first guy that contacted me was really enthusiastic on top of being first, so he gets the first look. The second guy though, what do I tell him if the car sells, or what do I tell the first guy if I end up wanting to see what the second guy would offer. And then how would I recontact the first guy to tell him I'd take his offer?