Hey Guys I want to put a splitter on the ole' hillbilly mobile. I plan to make it out of 1/4" think ABS plastic, I know many of you guys do that weird autox and road course thing, and do your own aero.

Im just curious as to what type of angle the splitter needs to be. IIRC I was told it has to be no less than 2* from flat, but you would know better.

Im been toying with a the idea of a flat under body, When I get under there to measure for the splitter Im gonna take some measurements for an undertray.

Any problems wit a flat underbody on a car that wasnt designed for one, any recommendations?

I notice alot of them OEM ones have vents, are they necessary?