Mother's cat got hit by a car...Help?

i have had many cats, and unfortunatly, (do to the fact that cats like to tear screens and we have no Ac so the windows are open in the summer) i have had many cats get run over, check his urine and feces for blood, and kinda give him a pat down, because, while, your right, cats are very good at hiding their pain, they will more than likley either flinch, or try to bite you if you touch an area that is seriously hurting, other that that, if his....excrements (is that how u spell it ?) are blood free and hes not obviously injured, he should be okay if u wait till monday, but definitly take to a vet no matter waht.