Im goign to paint some spray on bedliner on my jeep just above the rock sliders and the underside of the doors and where the bottom of the door hits the body (sorry dont know what its called) is there any prep work that needs to be done?

 

Scuff the **** out of it. Use sand paper, a scotch brite pad, or what I used was a surfacing disc on my angle grinder.

 

just follow all the instructions on the can.

basically you want to sand paper the old paint. wipe it clean. put first coat. let dry. sand lightly. clean. apply second coat. and so on. the directions will be on the can. read and follow them. the biggest mistake people make when applying the stuff is that they get lazy on the prep and it peels off.

I have had mine in the location for about 3 yrs and it still looks good.

 

Ditto. I was going to say I did bed liner on the inside of mine. Followed the instructoins to a T and it worked out great. Dont get tired and cut corners. The prep is the key to a good long lasting job.