Gilly,
I,think you have a point there.
Most well known tuners esp.Benz tuner(Porsche too)
specialized only in one particular marque.They
special order springs w/there own specs.
For they know what power,how low,how heavy etc.
the car will be to meet the customers demand.
Besides they are very reputable,they can charge
more $$$$.Same as tuners wheels.One place to go.
OZ wheels.Only an opinion.

Clauser1