Seems like one of the many, many ways BMW dealerships come up with to rip off customers.
I did a quick Googling, and apparently it's "only available to dealerships." I have NEVER seen a dealership with a competent detailer on staff.
That's a major red flag to me. If it's a good product, why not try to sell as much of it as possible? Or is it because they realize that if someone did a head-to-head comparison with any of the other major sealants out there, Cilajet would be found to be equal at best?
Bottom line, you can sell those douchey, brand-whoring BMW owners anything, so long as you convince them it's "exclusive." YMMV.
EDIT: Just read online that some BMW stealerships charge $1000 for an application of this stuff. $1k for a wash, strip, clay, seal? LMFAO.