What would cause the front bump stops to disintegrate like this?
 

My ‘00 S is in excellent shape all around except for this. It has just 68000 miles so I’m surprised the bump stops are falling apart. Any thoughts on the cause?

Other than the fact that they're 20 years old?

I have no idea.

Just sayin'............

TO

p.s. of course I'm being a smart ass, but parts like this do deteriorate over time.

Why just the fronts then?

The rubber used in the suspension parts on these cars is junk, which seems to be common with German cars. Rubber degrades over time, and whatever specification of rubber that Porsche used on the front bumpstops degrades even faster than the rear rubber. As TeamOxford mentioned, your car is 20 years old now, so they are falling apart.

20 years of temperature, ozone, light, and stress.

For the same reasons, the rest of the rubber suspension components are likely to be (or soon to be) in a similar condition.

Mine were that way too, as in they were virtually completely gone with just a few shreds. The backs were actually pretty good still, and this was at around 110,000 miles on a 2000 S. They look to be made of the same foamy stuff, so don't know why just the fronts? They were pretty cheap so I replaced them when I replaced the struts.

Mine were the same at 46K miles. Itsnotanova (Woody) advised that they are shot in every Boxster he has seen.

I had a set of expensive shoes probably 10 years old. Used maybe 8 evening a year. Put them on and they felt funny. Both rubber soles were disintegrating, coming apart in little pieces. Not the first time I have seen that happening.