If 'Darth Vader drove an XJS, he would probably have one of these!

This morning I had to get a Bulb for the Side Light on my Merc and came away with this Amazing 'Light Stick'

Well worth the £20 that I paid for working on or under your XJS.

It has a Couple of Magnets to Secure it under the Bonnet/Hood and also a couple of hooks on each side if you want to hang it somewhere.

Plus an On/Off Button each side. (so you don't have to reach over)

For power you plug it into a Cigarette Socket or you can buy an Adaptor, so that it can be connected with Crocodile Clips £3.

Its so good that I used it to Underseal the Merc in Total Darkness for its MOT tomorrow like you do.

Its called the 'Work Vision' and has two strips of LED's

Should be available at most good Car Accessory Shops.

 

Those lights are great, I was given one a couple of years ago, excellent in every respect. The batteries will last an easy few hours too.
I thought you may have been referring to something like this:

 

No 'Internal Batteries' needed, it works straight off the Car's Battery and as 'edgy' as that XJS looks, 'Darth' would just be using that as his 'daily driver'

His other Car would be something like this!