I grew up with these cars and had a fair few. It was when Ford used to make fairly quick cars (pro rata with todays models) without a Porsche price tag and without any input from the Co2 bashing brigades that exist today.
They were awesome cars and well capable of beating a lot of very renown and much more expensive cars in standard form. Once they were "chipped", that was it, they were in a totally different league. Forget your Porsche 911's, Lancias Thema 8:32, Intergrale, M3's, M5's, Merc 500s, 24V Senator/Carlton's. Cosworths were cheaper and faster.
In the 80's and 90's car security was simply shit and anyone that wanted one just had to basically find one parked up somewhere. It wasn't just Cossy's but Austin Metros, Astra GTE 16v, Escort XR/RST and the list goes on. Joy riding was all the craze with insurance companies eventually sticking their fingers up with new premium prices that'd cost more than the car. From memory the Vecta was a common immobiliser and easily bypassed. It was either that or a Harry Moss alarm
I can't really remember what year it was but around late 80's - early 90's but my Insurance went up from something like £400 to over £4k. It didn't help that I had a licence that had a Welsh accent as it'd been to Swansea so many times for speeding. I was in one of the national papers for allegedly travelling at over 140mph and found not guilty. Only to be done later for 124 by the same copper.
The insurance was so expensive, people used to go without it (I didn't). If you came across the Police who wanted to pull you, you just went into 3rd gear, squatted the back end down and just went up the gearbox. A few corners later they wouldn't have a clue where you went.
That's pretty much were the bad boy image came from with the owners. After the Cossy's it was then taken over by Evos and Scooby's.
They were uninsurable to some and got so cheap that you could pick them up really cheap. I had 3 at one time but they were a liability and made way for more practical cars. The favourite and alternative legal way to drive one was to get insurance on another car, with the policy enabling you to drive "any other car" Insurers soon done away with that and even not allowing traders policy any cover.
It'd be interesting to know the final numbers made to the numbers stolen.