I'm going to install the targa bar vinyl on the targa bar. I've seen people say to use 3M adhesive and others say it won't hold up. Opinions? Also I've seen people say to use scotch bright to scuff the panel first? It's newy painted. I hate to do that. But I guess it helps, yes?

If you are using all the trim the 3M will work. The edges are held down.

I have tried 3M 74, 77 and 80. Not happy with 74. Both 77 and 80 worked well.

They have a spray adhesive specifically made for glueing vinyl, don't use anything else.
It will say on the can if its for vinyl, if it doesn't say for vinyl don't use it.

Seems pretty straight forward, but yes read the can.

Results may vary. Follow the instructions.

I used 3M adhesive that was OK for vinyl and it didn't stick well upon application. I pulled it up and applied more. Bad move. It somehow created bubbles under the vinyl, so I pressed it and rolled it, finally getting it to seat, but 4 years later, its coming back up.

Thanks. Can anyone tell me if the scuffed the panel before applying the glue?

The factory didn't. You may want to take wax off the area though if you did that. Clean and dry the area really well.

Also, don't assume the shape is right. Test fit the panels dry before applying.