Is 178000 miles good for a 2002 Bonneville

What are you asking? Are you looking at buying a used car? Mileage is a hard thing to gauge. Some vehicles are well-known to go to 400,000 miles with sporadic maintenance. Mine just hit 401,000 two days ago. Some cars can barely make 150,000 when you take meticulous care of them. In my book 178,000 is nowhere near the end if its life although you can expect repairs related to high mileage to be needed just like on any other car.