Well my point is, I WILL take some short cuts, this wouldn't be one. Not because I wouldn't fill that rust with bondo, but because it wouldn't last so I would be wasting my time. I WILL take a short cut, if it doesn't look that great, that is my business, you know what I mean? If I want to look at a big brush touched chip in the door of my car instead of fixing it right that is up to me, it's my car. But I wouldn't take the time to fill the rust in the door of my car with bondo and paint it because it would be wasted time, it would fail way too soon for my liking. If it would last years, I may just think about it, but by the odds it wouldn't, it wouldn't last but a few months before it started failing. That is simply not a good enough end result for my hard work be it a short cut or not. I have done some awful funky stuff on my own cars, if nothing else as a test bed.
Heck, in my Rambler it had a floor on the drivers side that looked like a sieve. A large area under the clutch and brake pedals was pretty funky like a friggin window screen. I sand blasted it, epoxy primed it with a brush and covered it with fiberglass cloth and resin then epoxy primed over that. That was certainly hack compared to the right way, but I figured in this old car (not like it's a show car) AND as a little test bed (and I am keeping an eye on it) I figured what the heck, I wouldn't have to mask the inside for painting, I wouldn't have to worry about welding in there with all the upholstery and carpet. I did a heck of a short cut, but with the educated guesstimate that it would last a long time and I still believe it will.
So there are times when you can do a quickie, it CAN work out well. I just don't think the benefits will out weigh the work, time and money to do this Saab anywhere less than right. And the thing about this is, I am not even sure it's worth it to do it right! If the whole car is full of rust, drive it and enjoy it and forgetaboutit.