I have a white Hyandi elantra, and I put an M20 on the back. I tested it with a LTI 20/20 and had pt like crazy. The unit was professionally installed, and I check to make sure it was level and square with the side of the car. The heads are about 14" apart to the top left and right of licence plate. I had pts at the licence plate and tail lights.
The unit is new, and I am very disapointed with it performance. My question is - I have two more heads ( the unit was a m40) would I get any better performance if the put a third head between the other heads?
side note : I get JTGs on the front with dual LPPs installed.