[speedjunkie]

My roommate and I used velcro cable ties from Office Max (or Office Depot or whatever) on our engine bays. Cheap, reusable, won't get brittle and break when heated, and we were still able to get them in black to match the engine bay and not be as noticeable.

The only issue is they may need to be trimmed on the sides in order to not bunch up, depending on how big the hole is. I didn't need to trim mine but I don't know how big the holes are you're referring to.