If its a manual, it will be the 10-xxxxxx number
If its an automatic (my condolances) it will be the 12-xxxxxx number.
What they are looking for is the model number of your car. In your case it is something like 123.123.1x.xxxxxx.
Look for a sheetmetal plate just infront of the radiator. All those numbers on there tell you about your car, and the options it was built with.
Hope this helps,
"...rationality of thought imposes a limit on a person's concept of his relation to the cosmos." -Nash
04/71 280SE 195k
09 Jetta TDI