Why would you say they are pointless? I do my own oil changes and I go by the lights, of course, I have switched to synthetic so the intervals are just right and not unbelievably long as the dealership likes them. The number of green lights decreases with time and the milage you have driven since the last reset. They indicate oil service and inspection depending on how long and how many miles it has been. I'm not sure about the e34 but on the e36 they are very easy to reset even without the special tool, so no trip to the dealership is needed.