My 2004 209 was already in this crack condition when purchased couple years ago.
JUst installed all new, the worst 1/2 of it all replaced with same stuff - pattern - stitching.
It all looked just like the link bigmac listed
My Opinion - women cause all of it.
They apply the worst chemicals hourly of suntan products - to what ever.
It's the number one vinyl killer.
Now let the Vinyl get exposed to hours of hot sun with fresh coatings of lotions embedded.
So now that new interior is done - New Rules...
No more sitting on bare seats w/o full terry bath towels - even if I have to sew on straps to keep them there.
Bone white towels - to reflect the heat of the sun when it's just sitting.
Replaced daily if needed.
Vinyl absorbs water & oils - Take it from there.
Bare feet are the worst for transferring dirt, water & oils into vinyl.