M1 Junction 5 to 1 South / Northbound

Hi all,
Drove up to North Circ yest and saw a black umarked 3 series pull over a cabbie just after junction 3, copper giving a ticket to the cabbie while his buddy was on the speed gun.

Coming back from the North Circ, saw a unmarked silver Insignia pull over another rnotor.

Just beware!