Sorry to hear your lights didn't work the way you wanted. Cheap stuff on ebay can be hit or miss, but i have had success with leds from ebay on many occasions.
I used 3M tape Intuit already mentioned to stick both my led halos inside my housing and my led turn signal light strips with success for over a year. Nothing has come loose, although i imagine one day it will. The 3M tape alows me to remove a light if it goes bad without possible damage to the housing, and i dont have any unneccessary screw holes either. Hot glue was an idea i had, but i was afraid vibration would cause my lights to fall off, so i chose the 3M tape.
You can buy a roll of it at your local oreillys. And no not terribly expensive considering how much you need, but expensive compared to other brands/tape. The stuff works really well though. Roughly 8 dollars for 5 feet of it.
I'll try. So another question, I might try the dual low beam conversion after all and I would appreciate if you guys confirm that I got it right. The manual says that the low beam wire is black/green and high beam is black/yellow. I attached a picture of what I think it should be like.