Hey guys I'm a new owner of an sl55 and I love it, so I'm just trying learn everything I can about the car, so tell me about this abc button do I keep it on all the time or what?

The real details are in your owner's manual.

ABC stands for Active Body Control. It is essentially an active suspension that keeps the body from rolling, diving or squatting under different loads. I have it on the hardest setting pretty much all the time.... but my gf calls any drive with me....... 'practice' or 'qualifying'!