What have you guys used to clean the headliner? I have a "mini" carpet shampooer, but I'm afraid it will cause it to lose it's adhesive. Any suggestions?

 

1 part Woolite and 3 parts water. Mix in a spray bottle. Spray on a MF towel and then gently scrub the headliner.

You're correct....the carpet machine would apply WAY too much liquid and would really screw up the adhesive. Use as little moisture as possible on any headliner.