I recently jacked up the rear of my car to replace the rear brake pads, and as I was poking around back there, I noticed that a hold had formed on the underside of my rear trailing arm around where the shock sticks through. The hole has eaten a little of the underside, but hasn't reached the top side yet. Seems to me that this is a pretty critical part that bears a lot of stress. I noticed that it's $800 through Performance Products and there's no way I could afford that. Is there something I could spray on the metal down there to slow down the rust and the enlargement of the hole? If not, if I could get my hands on a used trailing arm, is it hard to install? Seems like a pain in the ass. I have no rust anywhere, except for this rear end part. Frustrating

Alex

__________________
1983 300D (parked for four years)
2012 VW Sportwagen TDI Manual
2001 Miata SE
1962 Chevrolet Corvair Rampside