Do the Caps & rotors yourself, they are indeed easy to change out. As to the tensioner, $400 sounds fine.

As to the motor mounts, I think I'd farm that out too, because if they're not done perfectly you could be inviting weird vibrations into your drivetrain.

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"If God had meant for us to walk, why did he give us feet that fit car pedals?" Sir Sterling Moss

Michael
2014 E63S Estate
2006 SLK55
1995 E500
1986 Porsche 944 turbo