Oh, and blocking the drivers side fog grille will also help keep air out of the engine compartment.
Some more pictures and questions:
What are these vents for?
I'm not entirely sure of the best way to do the intake mod that prevents air from entering the engine bay and just pushes air from the grille. OTOH, I could open the grille back up and block the intake, and it will pull warm air from the engine bay. Here's more pics of the intake, I found a cover that comes easily off the top:
Actually, I think I will just block it in front of there. I'll lose the tiny amount of possible ram air effect that I hope would reduce pumping losses on the highway, but I'll gain lukewarm air intake from the engine bay. If I want ram air, I'll do a complete ghetto ram air later...
theholycow, can you get away with the plate in the drivers window in your state?
if so, you should use some cardboard to make a template for across the front bottom to block that entire section out. (foglight opening to foglight opening) it looks like its indented a little so it shouldnt look out of place if you paint whatever the final fitment material is black. can also try and use some sem texture paint to give it a factory black piece look too. but as long as your not driving through the desert, those two openings that you have blocked off now, opeing those up with the bottom completly blocked should be just enough cooling for you.
as for those brake ducts, i wouldnt worry too much about them. theoretically its low pressure to low pressure so i dont see you gaining too much from sealing them up.
I don't want to relocate the license plate to inside my windshield. It would annoy me there, and worse, it would attract unwanted attention. I prefer to look as invisible as possible.
By "those two openings that you have blocked off now", do you mean the fog grilles or the small openings behind the upper grille?
The bottom opening is indented a lot, even at the part between the fog grilles and the main lower grille, so I could certainly fill it and make something that fits flush. I think I would have difficulty coming up with something that doesn't look completely hacked, I'm pretty sure the fog grille covers I was working on are actually going to look awful too. It definitely sounds like a great idea if I can pull it off, and just have the upper grille for all my cooling. Plus, if I fill it in, then the license plate would be fine, I could even skip the mount and screw it directly to the car and have it flat against the surface...
The underside of the car is pretty decently smooth, it has semi-smooth (actually golf ball dimpled) partial pans running most of the length of the car for ~18" on each side, but I figured if people are adding belly pans and getting results then I could gain a little if I block the brake ducts and add a small wheel deflector too.
Your fog light inserts are probably easy to remove, so instead of taping stuff on top of them, if you want to do a clean job, you could take those out, and then fill them/cover them/ shape them, then put them back on.
You could even do fiberglass mold and make a flush replacement filler part, and paint it, if you want a good look. Could even do carbon fiber look .
In all those grill mods, what's the real MPG savings? Noticeable?
You're right, it makes far more sense to take the fog grilles out and either attach stuff to them or leave them out and attach stuff to the stuff behind them. FWIW, I certainly have no interest in actually driving with just the taped-up stuff, that's just filler to go behind whatever less ugly surface I use.
I can't do a fiberglass mold because I have no idea how, and I'm absolutely awful at fabricating clean lines. I can't even cut straight with a tablesaw, or draw a straight line or circle with a pencil (though I can with a pencil and a ruler).
The only mods currently on the car are the lowered license plate and the blocked openings behind the upper grille. It's going to take at least a week for me to measure the result at the gas pump.
yeah, i meant the foglight grills. but ive been thinking about it and maybe blocking off the entire bottom isnt that good of an idea. thinking of how racecars route their radiator ducting, do you ever see it near the top of the car before the hood? 90% of the time its at the bottom where your highest pressure will be. so maybe just blocking off the foglight holes and then keeping the blocks you have behind the grill is the way to go.
you could possibly even go as far as getting a junk vw grill, wrap it with fiberglass and resin and leave the upper part on the drivers side of the grill (where it would meet the hood) open so that it utilizes the factory air inlet. sand it all smooth and paint it the color of your vehicle. put the vw emblem back on too so it "seems" factory.
Based on the time of the post, I'd guess that you didn't see the second mockup and are responding to the first. Besides the fact that I could never make it happen anyway, it does look nice, but it's not the invisible blend-in-with-everyone-else look I'm going for.
The second mockup where I only covered the fog grilles looks much less conspicuous, only slightly out of place. The angle of that picture might help, though; perhaps the angle of the first mockup emphasizes the sub-bumper area too much.