1999 cadillac deville leaking rear seal
 

Engine seems to be leaking oil at the rear main seal. Engine only has 7,000 miles on it and leaked almost immediately after installation. Engine manufacturer says the flywheel may have been installed incorrectly. Is this possible? Don't the bolt holes prevent you from doing this?

"Incorrectly" can mean a lot of things, but most likely, it was meant to mean "Not properly torqued, or overtorqued", which can distort the rear crank hub, and cause a leak.