Hide a spare and King antenna replacement

i reserved today to work on several mods I've been collecting parts for over the last few weeks.  But I didn't get very far on some of them. First up is the BAL 28215 hide a spare.  I found great instructions posted by someone and cut the bars down to the proper length , but the unforeseen onstacle is that my spare is 8 inches tall, yet the most space I can get with the provided mounting plates is 6 or 6.5 inches. If I lowered th plate anymore, I could only use the top two screw holes. . I don't think the bars are very flexible to wrap around the tire.  Do I have to add plates so I can drop the whole setup a couple of inches? Or maybe I can drill new holes in the plate? Second is the king antenna OA8501. I got the old wing off and my new hole drilled.  But there doesn't seem to be a wire that connects to the booster. I'm guessing that the red wire I unhooked from my previous antenna is related to that.  Do I need this for the new antenna?  Thanks.