I loaded my kid's bike into the back of my GL320 and got grease marks on the carpet and on the back of one seat. What's the best way to clean them?

Very simple...Autoglym Interior Shampoo/Cleaner. It's the only product I've used since 1995 to clean upholstery. It's safe, gentle, and effective. Leaves the surface clean and soft when complete without any odor or tacky feeling.

Spray directly on the surface, let it sit for about a minute, then gently rub with microfiber towel. Repeat until the carpet is clean.

http://www.glisteningperfectionstore...ttle%2C/Detail

There is no need to worry about it...There are many types of cleaner available in the market go and bring the best one and that will help you in taking out the greace mark from seat as well as mat..