Anybody ever try to make one aerodynamic, or is it worth the bother? I was thinking that cutting a section from an old blow-molded skylight to fit the contours of the front end would give a pretty good result, but I haven't tried it yet.
I could probably find a skylight for free, but I'm on a super-tight budget otherwise and there are too many variables in my area (hills, temperature, traffic) to conduct effective A/B testing.
I have a master plan for this that I haven't implemented. At Home Depot, I found some house address stickers that have the same size/color/background reflectance as my California license plate. I intend to remove the plate and put it in the dashboard like all the rice-rocketeers, and put the address numbers/letters on the bumper. The letters on the bumper will have a "long rectangular" European look.
This way I will be complying with the spirit of the law (a license number that is easy to read day or night on the *bumper* of the car).
When I was fiddling with different grill block designs, I thought of it. See second and third pictures below :
You should really check your state law befor doing anything to your license plate, alot of states require that NOTHING be placed in front of the lisence plate numbers or experation stickers, this includes solid or clear covers.
you might be able to get away with forming your plate to fit your bumper better, but if your plate is not clearly readible unmolested exspect to get a ticket.
I left mine in the stock location as the bumper is pretty flat there, but really, if I lowered it a little it would fit right in to the grill block.
If the airflow remains attached around the front of the car a flat license plate won't make any difference in aero. I suppose a total flush mount system would look neat and make you feel good but it won't make any quantifiable aero improvement on most car front ends.
I think it does make a difference. Imagine an air molecule hitting the front license plate, it has to be pushed aside with a 90-degree angle, which costs energy. If the angle is lower (as with a rounded plate), less energy is needed to push the air molecule aside - or in other words, the pressure on the license plate is less (check those graphical representations of pressure around a vehicle, it's main high pressure/red areas are on the front end of the vehicle where the air hits straight on). It's like with a windscreen, the lower the angle the better.
Also, with a 'rounded' licence plate the air will remain attached better than with a straight plate.
To avoid troubles with the law perhaps it's possible to beat the license plate with a hammer into a slightly rounded shape.
i'm curently design a cover plate for a depression in my front bumper that will fair the licence plate into the bumper. legally i can't do much to the shape of the plate so i have to work with the space around it
this is what it should look like when finished (also note the grill cover that curently is only tape...the 2 top rows are closed on the back anyway!, and the airdam extention that shouldn't be to hard to make once i find a suitable material):
my initial idea was to just cover the depression, but since the licence plate is in front of it i decided to design the cover so that it would make a smooth transition between the edges of the licence plate and the lines of my bumper.
i doubt this mod will produce any measurable gains but i don't think it will hurt either.