After installing a Teyes Android unit in a 2010 B180, the extra power and adjustability of the sound showed up how much garbage the factory speakers were. It had a Command 20 unit that I ripped out and speakers were next. The speakers were probably the cheapest things ever.

For reference the front speakers (non- HK) are 6.5" and the rears are 5.25", although I understand that 6.5" units might fit in the rear doors as well.

I've installed Kicker 6.5" KCS650 2 way speakers and its truly day and night between these setups. The Kickers came with adapter plates which went straight on (no hardware provided). There is plenty of room to drill extra holes if you want to make sure they'll never come off. These new units can be soldered or crimped straight onto the existing wiring so there is nothing to change except making an extra hole in the adapter to send the wires to the back of the speakers unlike the factory units that connnect at the front. The old speakers came out easily once you've removed the rivets with a 5.5mm drill bit.

The Kickers have a bottom mount depth of 54mm before the adapter of 16mm so they fit easily and leave plenty of clearance for the movement of the window.

You'll need to use that same drill bit to enlarge the holes in the door panel and use 6mm bolts to attach the adpater. The speakers then just bolt to that and you're away. The adapter was 16mm in depth. Plenty of clearance at both the front and back to clear the door card and window at the rear. The only tools you'll need are trim removal tools for the doorcards, torx sockets, screw drivers and some cutters, drill, tape, solder or crimping hardware. Wiring is easy with the MB solid green color wire is positive and the wire either black or with a black line along it, being negative.

Old speakers didn't state wattage but were clearly marked 4 ohms impedance.

Next will be changing out the rear speakers and maybe an amp. Link to those installed. They sound brilliant and have transformed the car's audio although the rears still sound crappy. KICKER | KS Series 6.5" Coax