The door seals and fold-down seat on E39’s are notorious for squeaks and rattles. Point them out and we will fix them.
Dash trim is available in Wood (PP), Gloss Black, Gloss Grey, Gloss Beige, and Aluminum. (M5) It is possible to change the trim with OE BMW parts after the fact but is very costly. Aftermarket kits can be considerably cheaper. Beware of fitment and quality.
Premature wear of the leather is a common complaint in E39’s, especially in cars with black leather. Some people have recommended choosing vinyl upholstery rather than leather.
Leather should be periodically oiled with a protector so that it retains its moisture. Dry leather is more prone to wear and cracking.