The Cortina Mk 4 "facelift" was officially known as the Cortina "80" when it was introduced (in 1979) but it quickly became known universally as the Mk 5 and that name stuck. Even dealers referred to it as the Mk 5 even though Ford never officially did.

I worked for a company in the motor business where many of us had quite nice company cars. A couple of people had Sierra XR 4*4s which had been tuned and had aftermarket belt driven superchargers - they went very nicely, though they needed servicing every 3,000 miles or so.

One day I was going somewhere with the chairman's son in one of them. As we went through one of the tunnels on the M25 he said, "Watch this", flicked the ignition off, put his foot on the clutch, pumped the throttle and then turned it back on, lifted the clutch and basically bump started it at about 90 mph in the outside lane. There was a huge explosion and a burst of flame from the exhaust, which in the tunnel was pretty spectacular.