Don't worry about it until you get a flat battery!
You can get a code easily but it means removing the stereo (and losing the
code!) first. It costs £10 - £15 from Vauxhall.
You might contact the previous owner and the original supplying Vauxhall
dealer as well. You never know, they might have it.
--
Alan
New & used Vauxhall cars & vans, servicing, repairs & parts
www.steeles.co.uk
Vauxhall CD players & handbooks
http://www.stores.ebay.co.uk/vauxhallradiosales