Kim Kardashian came face to face with a vehicle that's even flashier than hers yesterday ... a California Highway Patrol car. 

Kim's brand new $300k custom Rolls Royce Phantom got the lights and sirens treatment Thursday afternoon when the CHP singled her out on the 101 Freeway.  It's unclear why Kim was pulled over. 

We're told the paparazzi (not ours) had been following Kim from a nearby gym ... but there was no high speed chase a la Justin Bieber ... and the cops did not go after the photogs. 

Didn't take long for Kim's car to attract the cops ... she's only had her new black ride for a couple of weeks.

From TMZ.com

Thumbnail via fashionbeautyglamour.blogspot.com

Picture via FlickRiver.com