A look at the skid plate and its attaching bolts, and a reason not to have auto shops do your oil changes.
Bolts / washers I used:
(4) rear bolts: M6 x 1.00 x 25mm body bolt, 10mm head (Lowes)
(2) side bolts: M6 x 1.00 x 20mm flange bolt, 10mm head (Autozone)
(4) front bolts: M8 x 1.25 x 20mm flange bolt, 13mm head (Autozone)
(5) bumper bolts: M6 x 1.00 x 20mm flange bolt, 10mm head, w/ fender washer (Autozone)
You should be able to find these at other hardware/automotive stores. These are not OE bolts, obviously.