TSB: 09-012/07 MULTI-MODEL - ENGINE UNDERCOVER HARD TO REMOVE APPLICABLE MODEL(S)/VINS 2004 - 2007 Mazda3 2006 - 2007 Mazda5 2007 Mazdaspeed3 DESCRIPTION On some vehicles, the undercover may be hard to remove because the clip-nuts are rusted on the bolts due to road salt. When this happens, the complete clip spins or the spot weld breaks and the nut spins separately from the clip when loosening the bolts. The clip-nuts can be serviced separately from the undercover, and modified clip-nuts are now available with the thread integrated into the clip base. When you receive a complaint that the undercover is hard to remove because the clip-nuts are rusted, replace the clips-nuts with the modified ones, and if needed, the bolts. There are seven bolts that hold the undercover in place - two along each side and three across the front. The modified clips-nuts are for along the sides. If the clip nuts across the front are damaged, replace them and the bolts, if needed. The bolts used for the sides and the front of the undercover are the same. NOTE: ^ The original bolts for the under cover (PN: 90720-0620) are 20 mm long. In place of these bolts 16 mm long bolts may be used (PN: 90720-0616). Although the 16 mm bolts are more difficult to align and install, less thread is exposed above the clip-nuts when used, reducing the chance of corrosion. ^ Before installing the bolts, apply anti-seize compound to the bolts. ^ Reuse the undercover if possible, however if it is broken, replace it with a new one.