All I know is, many garages use a " Mitchell " manual, to establish labour " guidelines ".
I've also noticed at the " Alldata " site, they use different labour rates for the same job.
One rate is for warranty work ( usually the lower one ), & the other ( higher rate ) for non-warranty work.
But, in all fairness, I know how stingy all OEM's are with warranty labour.
Have listened to many mechanics ***** about this ( rightfully so in many cases ), for a lot of years.

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2007 C 230 Sport.