My wife bought a stain remover to use on baby poop and other stains, for when our baby comes into our lives in May. It’s called puracy natural stain remover.
I noticed that my seat (driver’s side) had lots of dye transfer from my jeans. Wife asked me to give this a go before I use lexol on it (I used lexol last time and it removed 90% of the stains). I used puracy on the affected parts, left it there for 2 hours (it says upto 8 hrs or more for heavy stains and 15 mins for light stains). Cleaned it up after 2 hrs and I was surprised. It got 99% of the stains out. Seat looks brand new once again. I did not expect it to work at all but it did and I’m a convert.
https://puracy.com/products/natural-stain-remover
I’m in no way attached to puracy. Nor am I trying to promote it. I thought I’d post it here in case it helps someone. If it doesn’t work for you, don’t blame me. It worked for me. That isn’t a guarantee that it’ll work for you
Edit - Our X3 has a streak on the rear passenger seat that’s been there for a few years now. Let me see if this will work on that.