i turn my headlights off whenever i get a chance, but it does seem to have a small positive effect when cops are looking for you, the thing ive noticed is if your approaching a cop from behind (so his POV cone is in front of him) with light son they seem to turn around a lot sooner, compared to turning the light off where you can get quite close before they turn...
i have a tendancy to hide in the garden just south of michaels house (where you can do the gate glitch) and when i leave my light on they seem to spot me, tested last night dropping my lights off and they just drove around for a while and then gave up, then got back to the gate launch
although these days its become second nature to take three lefts followed by three rights and it seems to shake them off pretty well
Might have a small effect, not sure. Going off of that I've read in several places if you're with someone (obviously share the wanted level) and you both get out of the car after finding a safe spot instead of both sitting there it supposedly speeds up the process a bit - no idea if confirmed or b.s.
No, but parking and getting out of the car will
My friends and i have tested this solo and while together, getting out of the car does speed up the process by a few seconds or more depending on how close the cops were you (or Both) exited the car to a hiding place
as far as the OP's question we havent tested this one, but we always kill the lights and radio ..just seemed like the right thing to do