The best thing is to know your paint type, condition and what damage it has. If the clearcoat is peeling, gone (dead) or cracked through to the primer, the only fix is a complete strip and repaint.
On the other hand if it is in good structural condition but hazy and or dirty, then polishing and reclearing may be your solution. I don't buy the clear will just peel off again argument one bit. This depends on three factors only, the condition of the underlying paint, the compatibility between OE paint and new clear, and the condition of the surface prep, i.e. clean no residual wax or silicates.
If the underlying paint is in good condition and not already peeling then a recoat will be fine. If you are using compatible paint/clear and not mixing lacquers enamels etc. again, your new coat will be fine, and of course most important in any paintjob is the prep and cleaning of the surface to be painted to make sure it is free from any compounds that will interfere with good adhesion.
Talk to people you can trust in the paint industry, not body shops looking for business that are likely to say the $500 dollar option wont do, but the $1500 option works fine
I've been restoring cars for over 20 years and have only had to completely repaint one vehicle out of 30 or so. I've seen many finishes claimed to be dead, gone, nullo only to bring them back to original glory with hard work and a good understanding of what I was working with, this is key in knowing what can or cannot be done to your car.
Generally German (BMW's and MB's) cars from the mid 70's onwards used two approaches to paint. Solid colors were usually shot in one coat. Metallic paints tend to be a base coat and top coat approach. As such, most solid color car finishes can be polished back to new condition by removing layers of damaged paint. Most metallic finish damage is in the top coat, sometimes polishing to remove minor hazing works but if it is real bad, then applying a new top coat is a likely solution. This part is tricky due to top coat types, and where your knowledge of your paint really counts, BMW used Lacquer into the early 80's and then switch to enamel, and these two types are not compatible with each other and should not be mixed.
Eight years ago, I had a minor dent in my hood from an absent minded driver backing into me. Had a paint ship fix the damage and then re-shoot the hood, to get that new look to blend in right with the rest of the car, they also clear coated the fenders as well. Eight years later in a metallic black car under the hot FL sun, no peeling or bubbling yet from the clear coat
