I think there's a car seat safety group but i was wondering if using car seat protectors under car…

Depends on the brand of car seat. Contact them.

I’ve mostly read that if you take the car seat out often & clean that there should be no marks. & often the protectors just harbor bacteria/mold under/between them after a while.

Thanks for that info. I don't really mind if the car seats leave imprints that much, not like its a brand new car lol. They just don't seem safe to me. And yes I saw that certain car seat company make seat protectors but not many do. I found one for the Britax but not the Graco seats

I’ve wondered this also maybe @squishymommy1 would know

Graco does not allow any sort of mat

Ok thanks