Replacing underbody panels

There are three panels: (1) under front fender cover; (2) just behind front, and; (3) rear bumper and drive area. The battery is behind the middle and before the rear. Of the three panels, the middle one was in saddest state:


The original fragments on the left was some sort of plastic backed felt. The replacement part on the right is a full injection molded part. The forward part of this middle panel bolts onto the rear of the front shield.

The washer of one bolt bent up so it almost became a 'wing headed bolt.' I lost a lot of time, at least an hour, trying to get it unbolted. Eventually I left it and just tie wrapped the left front and right front bolt hols as the auto shop was going to close soon.

I have three, leftover 10 mm bolt-washers and will use two tomorrow when I replace the forward underbody shield. The replacement part lost two former wing corners out toward on the rear by the battery. When fixing a 2019 Model 3 with parts in 2023, 'some creative assembly is required.'

There is always a tradeoff between a specific fit part and two pieces that assemble to handle both Model 3 and Model Y. In my case, I will use exceptionally heavy duty, duct tape along the bolted joint between the front and middle panels to minimize drag and splash water incursion. I am also OK with replacing some 10 mm bolts with plastic tie-wraps. They are strong, light weight, and easily replaced without a socket wrench.

On my 'to do' list, I have 3d party, lighter, stronger, drip-water proof, front links to replace the OEM ones. I may do them before repairing the front, underbody shield. I had already massaged the grease fitting on the passenger side link to eliminate the body squeak but on the first freezing morning I may have heard the driver side.

Bob Wilson