Printing to Avery 1105 Wrap Vinyl with 1360 Gloss laminate. Heavy black areas look brown - Tried 100K, 60/40/40/100 CMYK and 0/0/0 RGB. Have also tried creating a new profile but it messes everything else up. Any ideas or suggestions?

#1 Can you attach some pictures so I can understand better the issue?

This sounds like it might be a problem with the way that your RIP is generating the black. One thing that you might try is to re-print, but selecting a "known good" cast vinyl profile in the RIP (for example, I think that there should be a profile for the HP Air Release Gloss Cast Vinyl) and see if there is any improvement.

If this results in a better result, it indicates that the problem is in the profile/black generation settings for the Avery 1105 in your RIP.