The adhesive failed on mine pretty soon after I installed it.

I used double sided tape like this Scotch exterior tape - no more issues.

I got rid of the audio cable and the 3.5mm headphone connector - it was never heavy enough to carry the power needed to drive the LEDs. I used some wire I already had, and bought a replacement connector

You will need to know how to solder (or know a friend who can) to replace the connector.

This is a good post that goes into more detail on replacing the connector.

It's a pain to have to do stuff to make the product work - but that's what happens with projects like these sometimes. If I had been willing to wait I might have been able to get ambivision to warranty it, but for me it was easier/quicker to just spend a buck or two and DIY.