Nice car! Once you drive a BMW, they say you'll never go back..
I wash mine, and in the winter it will be going through the touchless just to get the salt off. Jet Black is a very soft paint and gets swirled to hell in tunnel washes. SG isn't as bad, but tunnel washes in general can do damage over time. With the SoCal weather, you should definitely wash it yourself.
If dragging out the hose and buckets is a turnoff, you can try something like Optimum No Rinse (ONR). Doesn't require a hose, just a 5-gallon bucket or two and some good wash media. Hit up the detailing subforum for more information on it (and the hundreds of other products and techniques you can use to get an amazing shine).