I decided to buy the cable and do the update myself.
After pulling out the stereo etc. I traced the wires back to the box which had been installed between the glove box and fuse box - there was plenty of room and the installation looked neat with inline fuses and proper connectors so it was a good start.
I had a few goes at connecting and finally got to the flash programming stage where it stalled, so I unplugged it all, rebooted my laptop but the same happened again. It turns out the device properties need to be the same as the com speed
During one of the attempts I made to connect, I tried it with the engine running when something a little odd happened. The parrot box had all the cables plugged in, and was connected to my laptop via the update cable but when the connection failed I unplugged the USB end of the update cable from my laptop leaving the other end in the parrot box and pressed the key and removed it to kill the engine but it kept running! So I pushed the key in again with my foot on the clutch but there was just a weird clicking noise coming from the front of the car, but the engine kept running so I tried a couple more times with no joy. It wasn't until I pulled the update cable (which was still not connected at the USB end) from the parrot box did the engine stop running..........does anyone know why this happened?