That's not an LOF job, so I would think it is in line,given the labor rates per hour charged on the West Coast,,,($140 to $150 ph at Mercedes dealers there).

I'd consider also, by your supplying the parts, he was deprived of the markup on them to which he, as a mechanic, was entitled, when considedring the price you paid, all things considered. (not implying he was trying to "get it back" by overcharging you on labor though)

Some shops won't allow that, as it puts them in a bad situation should the part(s) fail after their install, as to their liability for it.

It's tantamount to bringing your own steak to a restaurant and asking them to cook it, if you ask me. I wouldn't do it personally, but then I would expect quality work from the mechanic, and the job done right the first time.

However, on occasion, I have asked them to install minor aftermarket accessories like a wood gearshift knob and a cupholder, but paid them their labor charges, and it was not a big job, nor a part that could fail, and cause an awkward bring back situation.

Look into a four wheel alignment, even a good Mercedes dealer prices these competitively, and make sure the wheels are balanced properly

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1991 560 SEC AMG, 199k <---- 300 hp 10:1 ECE euro HV ...

1995 E 420, 170k "The Red Plum" (sold)

2015 BMW 535i xdrive awd Stage 1 DINAN, 6k, <----364 hp

1967 Mercury Cougar, 49k

2013 Jaguar XF, 20k <----340 hp Supercharged, All Wheel Drive (sold)