BS! The place that does the $399 is the best in the nation. Official BMW Perf Driving School installer, and where LLumar sends it reps to learn the process...
$399 is just for their bumper only package. You want full hood, fenders, mirrors, etc and it costs $2k. That's the best way to go because bumper only doesn't protect your hood from all the rock chips and if it goes through the primer on the hood you can have rust.