Well, apostrophes are very very often used in a wrong way in both English and German.
This is a very good website about them, with a good links list as well: http://members.aol.com/apostrophs/
The sad point is that enough people have abused apostrophes that Duden changed a rule and made them "correct" in terms like "Rudi's Blumenladen", it says.
The American rule about the plural of abbreviations is another example of "appeasement" in orthography, though.
I'm in a conflict myself because my website is called "H-Trainer's RC Modeling Website" ( http://www.H-Trainer.ch.vu
) for the English version and I'm not sure about a suiting German name yet. To keep it correct German I'd have to call it "H-Trainers Modellbauinternetauftritt", or what?
What du you think, is it tolerable to write "Modellbau Website"? I guess "Modellbauseiten" would be more correct, but it looks less attractive, though. Any ideas?
BTW, have you seen the label "Bauer'n Hof" ? If it wasn't that sad, I'd laugh my butt off ;)