I agree, anything over the stock Becker is an improvement. I just received my Blaupunkt Nevada from Crutchfield (for my '86 190E 2.3-16V). Looks to be a straightforward installation. Crutchfield is great -- both their tech support and the fact that they sent the unit with factory OEM wiring harnesses

As for the antenna, I used some silicone spray on mine. Gave it a generous spray, then wiped it down. Both extend and retract seem a lot smoother.

Brian