cant find oil leak
bought car after being hit by uninsured driver. had it since may 2010. Noticed it used a little more oil than I liked, someone changed oil and said it had a bad leak. I got a bad feeling about the person who changed the oil because I never saw oil leaking from the car. She said it needed the front crank seal?, the seal where the timing belt is, so I had that seal/belt changed by another person, She of course wanted 4 times what overs did. I see oil on the ground still, cant see a LEAK persay but do not know what the next step would be. Nothing coming from top, nothing in plugs. This is really bugging me. Not one honest personal locally to help me. Any advise, book or reference. I am an old tech so if someoen can give me a reference I can find a way to fix it...HELP