Hello all. Long story (semi) short here, I have been dealing with a mysterious handling issue for the past couple years, and despite a whole lot of tinkering, multiple trips to reputable shops on both sides of the Atlantic, and a lot of money spent on replacing bushings etc, it would never go away. The basic problem was that the car started feeling unstable at anything more than about 50 mph. It behaves as if it is being randomly pushed around by strong winds, knuckleballing down the road, and basically refusing to track straight and true. The problem surfaced in the middle of a long drive initially. One minute the car feels fine, next I'm thinking "man it got windy all of a sudden". Then I stopped for gas and realized there was no wind, at all.
A few months back I thought I had finally found the culprit, as when I removed my tow hook license plate holder to switch to a European format plate, the problem immediately improved noticeably. For a couple days, I thought it was gone, but soon realized it was still there, just not noticeable until higher speeds. The start point had moved from about 50 mph to around 90 mph. The fact that I now live in Germany makes that more of an issue than it might have been back home in the states, as I regularly cruise at around 100 mph, and would drive faster if the car wasn't all over the place.
So the license plate issue clued me in that it was aerodynamic. I had originally thought it was suspension or alignment related after finding nothing wrong with any of the bodywork, and the other day it finally revealed itself. In the front of the car, there is a black plastic indent directly under the front license plate area. This is an area I have inspected many times over the past couple years as I washed the car, and never saw anything out of the ordinary. I guess a particularly fast run on the Autobahn the other day finally pushed things far enough that the issue was visible. This black plastic section is now visibly separated from the surrounding painted bodywork on one side, and inspection reveals that at least one of the clips that hold it together has snapped, and another one has been popped open, but appears intact. So, basically this section has been opening up on one side only and randomly allowing air through the bodywork, throwing off the balance of the aerodynamics for moments at a time, and causing the erratic behavior. I suspect that the off-center tow hook plate holder might have been shunting air forcefully into that corner, and might have been responsible for the initial failure of the clips connecting the two pieces, as well as magnifying the affect while it was still on the car.
Now the question becomes, how do I repair this? The clips that hold this piece on are molded into the front bumper, and they have failed completely. The factory's answer to how to fix this would be to replace the bumper, but with paintwork, clear bra replacement, etc, that is a rather cost ineffective method. I need to figure out how to lock these two pieces back together in a way that will not fail down the road due to the air pressure applied on an autobahn run. Things that have crossed my mind so far range from duct tape, to glue, to even taking the whole bumper off and fiber-glassing the parts together.
So, anyone have any thoughts on how to best repair this?