GBird,
I have the same accessory wire wheel covers on my 55, and yes, they are a pain. Not to mention replacement clips are almost like gold to replace.
What I've found that works for me is to use a pair of pliers to close up and reshape the end that fits on the wheel rim. The end tends to bend more open with use, and simply won't stay sandwiched between the tire and the rim. Once I close it up some, I force it onto the rim's edge between the tire and the rim.
Check one of the online catalogues of TBird suppliers for pictures of what the ends of the clips should be shaped as, for that is what I aim for when taking the pliers to one.
I find also that most of my clips, 3 or 4, usually don't give me an issue and stay in place on the rim. So I clip their other ends to the back of the wire wheel cover first. Then I force/wiggle the loose clips (one at a time if more than one) onto the rim, and clip their other end to the wheel cover, and do the same with the remainder.
I also found that rotating the wheel cover makes it easier to hook the retainer clips to the back of the wheel cover, allowing the clip end to fit between the fake spoke ends, where it usually would not hook on the cover because a spoke end was in the way. (Make sense?)
I also leave the clips on the rims when I store the bird over the winter. I remove the hub caps and the wire wheel covers to storage at my home where rust won't pit them. To keep the clips in place on the rims, I run a wire or heavy string/shoe lace, around the ends of the clips and pull it tight. The string acts as the wheel cover does to keep the clips in place on the rim.
To make the string even tighter and secure, I then run another string from one side of the original string to the other side and pull it tight and then tie it off. Saves having to mess with reinstalling the clips next season. Hope this makes sense.
Good Luck!
