See why Tyga's baby mama's Rolls Royce was impounded by the cops

Tyga's baby mama has some 'splaining to do ... because Sunday in Malibu she got their Rolls Royce Phantom impounded -- for a really dumb reason.
Law enforcement sources tell us Blac Chyna was pulled over after cops got complaints a matte black Rollie was being driven erratically ... and since there aren't too many of those $300k whips toolin' around, they quickly found Chyna and pulled her over.

That's when the real trouble began ... during the stop, cops ran BC's plates -- she was driving without a license, so they impounded the vehicle -- and will only release it to a licensed driver.
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