My XJS can sit for weeks at a time without me starting it and I was wondering if there is a recommended additive I should add to the oil for upper cylinder lub to reduce wear. Any advise would be appreciated.

Also, while I'm here, on both my XJS' the carpeted battery box cover is/was loose. Getting a couple of self tapping screws is no problem but it appears there was a bar of some sort across the front of said battery cover which would be held in place by the two screws. Again, any advise would be appreciated.

Stephen

 

Stephan,
The factory had half turn plastic fittings that held the battery cover in place.
I attached a parts diagram that shows the parts, My battery cover has long since been missing the plastic retainers but I don't have a problem keeping the cover in place.