Those that use the rubber mats and liners don’t usually have the issue that the carpet mat users have after long use. As mentioned above…it appears that the material that the Velcro is adhered to on the back of the carpet/velour mats degrades over time…and the Velcro doesn’t have enough material to stay secured. M3orPorsche mentions having the Velcro pad sewn onto the backside of the carpet…which can be another alternative to trying to make it stick to a failing surface.
I also discovered decades ago (in regard to the rubber mats) that BMW has usually offered two designs. They sell the ones in the parts department (which Ive never cared for that design) while there was another rubber mat sold in the parts database that usually had a different design for each model. I’ve always preferred that design and ordered the model specific rubber all-weather mats versus the ones sold at the dealership. The rubber mats for my e34 & e38 looked similar…but my e39, e53, f06, & f15 all looked different. But if I had gone with the ones from the dealership…they all would have looked alike.
{e38 rubber mats}
{e39 rubber mats}
{e53 rubber mats}
{f06 rubber mats}
{f15 rubber mats}
Then there’s also the plastic liners which are usually the ones designed by WeatherTech…but will have the BMW label on it instead. I hit the jackpot on my f15…it had the plastic liners (front & rear) installed and the box they came in was in the cargo area that was pictured in one of the seller’s images. When I went to check out the vehicle…the box was still there and when I peaked into the box, I could see a set of the rubber all weather mats. I asked if I got to keep the box if I purchased it and they said yes.
When I got home with the vehicle and pulled the rubber mats out to check them out more thoroughly…the carpeted mats were also down inside…still in the sealed plastic bag and had never been opened. I ended up using the rubber mats instead of the plastic liners