I think a lot of it depends on what you want the car to be and also your personal definition of "good enough." Me, I don't want my cars to be so nice you are afraid to drive them or leave them unattended at a show or grocery store parking lot. I just found a spot on the underside of my body where the car evidently came down on a speed bump and my reaction was "oh well!" It didn't bother me at all, as I fully expect those kinds of things to happen if you actually use the car.

My Nephew has an original '67 Shelby that is a very high point car, one of the best in the country. So, he keeps it in a climate controlled garage, trailers it in an enclosed trailer to a show, wins his trophy, and then tucks it back in the garage, where it does nothing but sit till the next show. If that is your idea of a fun car, great. Not me...............cars were made to drive, get wet in the rain, get hit by the occasional rock, and generally used as they were intended.

So I guess the answer to your question is, "the car is straight enough when you decide you can accept it's flaws (and there WILL be flaws) and you just want to get it on the road before you die."

Don