UK Car Repair Questions? Ask a Mechanic for Answers ASAP
There are only a few ways to obtain the code for these stereos if you do not have the original code card for it
As you do not have the log book yet, it is unlikely you could obtain the code at a main dealer, it is likely to be the most expensive option anyhow.
The easiest route I know, and this is the route I take for all the vehicle codes I need is http://www.radiocodes.co.uk/vauxhall-radio-codes
Your code is listed and would cost £22.
If you need the vin number, you will find this on the id plates and the lower passengers side of the windscreen viewable from outside.
The only other options are using a diagnostics computer capable of working on all systems to extract the code over the vehicles bus network or to disassemble the stereo and read the chip using a reader/writing chip programming tool and decode it manually.