Audi A4 in for suspension installation – Bilstein B12Next thing you know we are asking the customer if he would like us to repair this corrosion underneath the OSF Strut Tower (the NSF also needed treatment, although it wasn’t quite as bad).A4 OSF strut top mount cleaned upAudi A4 B8 Strut Top mount with Rust Encapsulator drying, before a coat of stone chip. This stuff is amazing.Audi A4 strut tower with stone chip applied. With rust encapsulator underneath, this repair will significantly extend the life of the car.