1.Put the car on flat ground, in park, or first gear with the ebrake engaged. Jack up the rear of the car with a floor jack or bottle jack using the rear jack points. Place jack stands or cribbing under the control arm. 

2. Assemble the center section of the diffuser. With the baseplate slots facing up, slide a fin on, with the hole on top. 

3. Install a black screw into each fin, tightening until the fin is flush with the surface of the baseplate. 

4. Hold the baseplate up to the bottom of the OEM valance. We will use the center hole of the baseplate, and the existing hole in the valance. 

Alignment will take some pressure. The diffuser needs to be tight to the OEM valance.

Using an 20mm bolt, slide the bolt in place and thread on a nut from the backside finger tight. 

5. Start on one side of the baseplate. Align the rear edge with the inside edge of the OEM valance. Then drill the outermost hole with a 1/4" or 6mm bit, and install a 20mm bolt and nut finger tight. 

Repeat on the opposite end. Again, apply pressure to push the diffuser tight to the valance before drilling. Then install a 20mm bolt and nut. 

6. Drill out the last two countersunk holes in the baseplate and install 20mm bolts and nuts. 

Then tighten all 5 bolts. 

DONE!

1. The spats are side specific. The countersunk holes face down. Hold the narrow end of the spat up to the valance near the wheel well. Align it to the inside edge of the valance, and to the edge of the wheel well. 

2. Align the back edge near the exhaust tip to follow the crease in the valance. Clamp or tape in place and drill the hole closest to the wheel first. 

Install a 20 mm bolt and nut finger tight. 

3. Check alignment on the back position again, then drill the hole closest to the exhaust tip. 

Insert a 25 mm bolt through the spat, through the thicker 8mm spacer, then into the valance and thread on a nut. 

Insert a 25 mm bolt through the center hole, through the thinner 6 mm spacer, and into the valance. Now tighten all 3 bolts.