Most of my benz buddies who do their own work to their car have this little pump or device where they can suck oil from the oil dipstick tube and not have to put the car up everytime on an oil change. Is there any downside doing this expecially with an old car like mine- 89 560?? Sounds like a greta idea but I want to know before I go out buying one. Most of my buddies all have newer Mercedes models.