From E30 Zone Wiki
The Front Valance makes up the front end of the E30's Bodywork. It is a detachable, bolt-on panel which sits behind the bumpers and carries the front foglights, if fitted. It also includes holes and channels to provide air to the radiator and the optional oil cooler. For vehicles fitted with air-conditioning, a special valance was fitted with a larger central hole.
Two types of front valance were fitted, depending on the age of the car. Cars of 1987 and before, known as pre-facelift, were fitted with the earlier style valance which has square cut-outs for the foglights. Vehicles after September 1987, known as facelift, have the later valance which carries different foglights as well as ducting to cool the front brakes.
It is possible to swap between these two valances, since the dimensions are the same, but this will also necessitate a change in bumpers. Each type of valance also determines what sort of body kit can be fitted to the car.
The Valance is a bolt-on panel, and is one of the easiest to remove. Everything is held in place with 8mm bolts, so you should only need one tool to get the panel off. However, you do need to remove your front bumper first, and that needs a T55 Torx socket.
Once your bumper is off, the car should look like this:
Now you need to get the headlight grilles off, by unscrewing the two screws on the front and then unhooking them from the headlights:
Your front end will now be a little bit exposed:
Now stuff your head in the wheel arches and remove the lower splash guards.
Then you can start unbolting the valance itself. Start with the screws just behind the bumper mounts:
Then the ones at the front edge of the front wings, just underneath the headlights:
Then the one behind the foglights:
And then the final mounting bolts just below the inner headlights:
The valance will now be loose, and can be pulled away from the vehicle. As it comes off the chassis rails, take the time to disconnect the wiring that runs behind it:
This will leave the front end of your car extremely exposed!
The new valance can now be offered up and bolted into place. As you do so, take the time to put copper grease on any of the hidden bolts, especially inside the wheel arch. This will prevent the bolts from rusting into place too much in the near future:
And that's it! Stand back and admire your shiny new valance!