When I bought my truck the passenger side rain guard was missing. I picked one up from the junk yard and put it on with some double sided tape. What's the best way to get it to stay back in the channel? A certain type of glue of epoxy maybe?

 

Rain guards? If you are talking about the seals at the base of the windows, you can get all four of them (inners and outers, both doors) for like 60 bucks at LMC truck.

 

I already have a new one, but it's held on by double sided tape. It's the only one now that's not "in-channel" and I wanted to know the best way to get it to stay in the channel because when I just stuck it in there it would start to shake out.

 

If they are the ones I am think of, they should clip down onto the door skin, they have 'teeth' that should hold them in place...... Pic?

 

I think OP is referring to the aftermarket ones that go at the top of the door to keep rain out if window is down slightly. Double sided tape is about the only way,....GOOD double sided tape. Check auto parts store for moulding tape.