I hear ya. I also have a 6 year old and 3.5 yrs old. I use the OEM cotton poly covers for the rear seats. Then I use another cover (with pockets) for the rear of the front seats so it doesn't scuff when they start kicking the front seats. The poly cover is durable and is a nice fit. Plus it only costs about $100. You can get from getbmwparts.com.