I've read many times here that it's not usually the plug wires that go bad, but the resistor ends, or "boots", which are very cheap to replace. I think the ends are just a couple dollars.
However, if you do decide to replace all of the wires, buy original wires at the dealer only. They are solid copper, which is why they are very expensive. The aftermarket wires, and even Bosch wires at Pep Boys, are a copper / silicone blend and don't last as long. FWIW, I've read many posts from the techs that original plug wires really never go bad. The thing to do is to just replace the boots.
The Mercedes dealer in Anaheim Hills is Caliber Motors. Remember the jingle on the radio "Caliber Motors in Anaheim Hills..".
I wonder if MB has a shortage on spark plugs wires right now. When Enrique rebuilt my head, I wanted to install new wires, but the dealers are out of stock, they are back ordered, and it will be a couple of months until they are in.
When I contacted Phil, he was out, too. Go figure.
I wish you could've made it to the GTG on Saturday. We had a good time, it was a good turnout, and we ate like pigs! Hopefully you can come to the next one, and we can admire all of the upgrades we've made to our cars.