You know what the UK flag, the "Union Jack" looks like? A rectangle with a square and a diagonal cross on it: A + overlaid on an X . Mini cars have that design, split in half, as the motif of their rear lights. (Half and a bit: The center vertical bar is replicated on the inner edge of both sides.) The rest, the center horizontal cross bar from the square cross plus half the diagonal cross, makes an arrow on each side -- pointing towards the other side.

Left side: ->| Right side: |<-

The -> and <- bits are the brake lights / indicators, so when turning left it flashes an arrow pointing right on the left side of the car, and vice versa.

Yes of course, I wasn’t complaining that it had ads.