the JPS mk2 capri,was officialy known as Midnight Special..with the gold pin stripe,and gold wheels,it became known as the JPS! everything was blackedout including the tailpipe! the interior was a gold vialto fabric on seats, but every thing else inside was black! u.k engines came in 1.6 ,2.0 ,3.0 from june 1975.as i said,at the meeting,not all were black! even rarer is the white JPS white bumpers gold stripes, gold wheels & seats.only a small amount made.these white versions,became known as Polar cats!
So yes your relation did have a White JPS