Speaking of extra gas....

Now that I'm commuting to work in my '87 Weekender, I really miss the 
range I used to get on my Audi 5000 -- 650+ miles on a full tank...

As expected, I'm barely getting 320+ miles on a full tank with the
Vanagon.  

Are there any safe and legal extra fuel tank kits for '87 that anyone knows of?
Thanks,
Cetin
cs@karin.att.com