The car still exists in police hands. It was recently revisited for further forensics. What is utterly bewildering is that it was taxed and MoT'ed until 1990. This says that it was maintained in a driveable road legal condition for four years after it featured in a crime, and was presumably driven. You have to wonder WTF that was all about. It's as though a gun were retrieved from a crime scene and then issued to a police firearms unit for them to fire off for a few years.
On a detail point, it doesn't follow that all Fiestas leased by Sturgis ended in GAN. I bought a new Ford in December 1985 and the dealer asked me what number I fancied on it: C920 HOT? C920 HOX? C920 HOW? I didn't realise the dealer had any discretion, but he explained that they had a range of them allocated to the dealership geographically. The 700 to 900s, I think, meant the West Midlands, while the letter combinations were to specific dealerships. That one had Hs that month. So C9xx Hxx meant Hangers of Birmingham.
If you think about it, this makes perfect sense from a DVLA (then DVLC) perspective. They've got to apportion the numbers from C111 AAA to C999 ZZZ somehow, so why not like that? They tell the dealer Here, use these numbers, and tell us which you use. They then know not only what's been issued, but also, who's got what plate that hasn't yet been issued.
Conceivably LE could find it useful, if they later become interested in a vehicle. They'd know if it's from outside their area, and if they find a car of interest, they could even go to the dealer who originally attached the plate and ask them if they remember the buyer, for example (did he look like Mr Kipper? Quick, nick Paul Young now!)
This is also why I am doubtful about there being any special significance to Cannan's made-up SLP 386L plate. As someone who'd been in the trade, he'd be aware of how plates worked and he might simply have been approximating a commonplace number / letter sequence for Bristol.
