Funny, I can only recall one instance where a customer insisted that I use one of their products to wax with...and that was back in like 1995!
I have no problem using their choice in LSP, but if it's something I really don't like I may try and talk them out of it or even charge more if it makes my job more work.
I will however not deal with people telling me how they think I should do my job...not that it's happened, but if it were I'd question why they were even having me do it in the first place.
Rasky (Chad):I would never, ever suggest or think about telling a Professional Detailer such as yourself, {or others (and I won't list them all) like Mike Phillips, David Fermani, Todd Cooperider, Superior Shine, Shiny Lil Dtailr (Charlie), Ivan Rajic, DJ Mayo, Renny Doyle, Todd Helme, Tim @ Performance Auto Spa, etc., etc.} what products, equipment, processes I think you, and the others mentioned, should use.
All I would do, if I may, is
inform you Professionals of is:
-What corrections/detailing efforts that had previously been performed; and,
-Who the gentleman/lady was that had performed such deeds
This I believe would be of some benefit to you, The Professional. This sharing of such information on my part would be, IMO, common courtesy.
With that out of the way, then I too would go away to await your call to pick up what I most surely will discover a most perfect of vehicle.
Bob