I have a 2010 T5 Volkswagon Van and there is no lock on the diesel cap.

I found one on the internet but is was $120.

Any other ideas please

Helen

I just got a lockable fuel cap from Super Cheap Cairns for $34. Not sure what one you want but there was a range for around same price. 

Neil

Hello adreamer

As woolman has already said.

Go into any auto shop such as Supercheap, Auto One, Repco etc
Park your vehicle outside, and ask the sales boy/girl to have a look at your size fuel cap, and sell you one.

If you ask for an original Volkswagon lockable fuel cap, you will have to pay top dollar for the name

Hope this helps you out