The dealer is going to fit a tow bar and reprogram the ecu. Can any one tell me what to look for to see if they have programed the ecu I have a trailer board on hand

With the Bolero you should see a trailer on the screen when reversing

If you have reversing sensors these should also not beep when you select reverse. Furthermore if you switch the car's rear fog lamp on and it should only illuminate on the trailer - the car's fog lamp should be deactivated.

If you've seen the tons of threads of the Škoda dealer network's incompetence in doing this coding I wish you luck in sorting it out the first time.

The car alarm will go off if the electrics are disconnected when the car alarm is on.

I found this pdf file and at the end it covers re-programming.

http://www.pfjones.co.uk/Wiring_instructions/29220508RC.pdf

Cheers

Jerry