I believe 4 point harnesses are not legal because in the event of a roll over were the roof caves in, it will cave in right on top of your head.
If you're wearing a 4 pt harness, your body will not be able to move to the side to avoid the and you'll get a severe if not fatal spinal injury.
Schroth, I believe, carries a street legal 4 pt harness. It is street legal because one point breaks away creating a 3 pt harness in an accident.
Awsome thanks for the info guys, I was looking at 4pt's cause I was under the impression 5pts wernt legal. Hmmm Soo technickly couldnt I take 1 strap off and tuck behind me if I go to get pulled over?