You must have a regular Vanagon.....lots of room just just drop in the Optima.

Westy's have the seat turntable base which is in the way, a small
slice has to be cut out.  Dremel with a cutting disk works great.

>I did no mechanical modification whatsoever... I installed the yellow
>top on its side with the metal posts facing forwards.  I did however
>put a few layers of black electrical tape on the edge of the battery
>indent so that there would be no accidental grounding taking place. :)