How can I get the terrible smell out of my 72 VW van?

[SammNaranjo]

I just bought a 1972 VW van that had been sitting for about a year outside near a field. It is completly stripped and so the smell is not coming from any certain place3 in specific. The previous owner told me that mice had gotten into it, but the smell is much worse than a years worth of mice. It smells like a combination of unrine and other things. Ive tried all the home remedies as well as buying deoderizers and airing the vehicle out! Please help!