>I just purchased a 1988 Vanagon GL , 7 seater and the middle
>seat slides from side to side on the rails, I've looked for a
>locking system ,but haven't found any . How do I secure it ,I
>must be missing some part ?

The seat attaches to the floor rails with four bolts which are apparently
missing on your van.  Not sure of the proper bolt size though.  Look at
the seat supports where they meet the rails and you will find the bolt
holes.  Go to the hardware store, try some metric bolts until you find
what fits, buy four and some washers, and you are in business.

Best wishes,

Tony

Anthony L. Mourkas
Hampden, Maine, USA
1984 Vanagon Westfalia
1991 Jetta Eco Diesel