I know on the E60 i had, the trick for this is to put the light swich to the parking light position (the one, one click to the right from 0) and that will leave your daytimes on with the rings on as well while you are driving, the inner ring won't be as noticable because of the fact that the daytimes are on but, the outer rings you will see just fine. Also you can turn the fogs on and off to give some aditional light output as well, and it also looks more agressive that way too .

EDIT: just noticed that you are in Jersey, if you don't have daytime running lights down there (donno if you do or not) the above instructions are the same, just that the center lights won't turn on when you are driving, making just the rings become more noticable.

Also when the car is parked yes you are right they can be let on, by keeping the swich in the same position, just remember to turn them off as they will not turn off by them selves. I forgot once and luckly the lights didn't draw much power cause my battery was almost dead, this was after about 8hrs left on too