Driving at night in the B on unlit country roads isn't one of the most pleasant experiences as the headlights are pretty weak.
However this can be improved by fitting relays to the headlight circuit which move the high voltage away from the switch, instead feeding power direct from the fusebox. I used the relay kit sold by the MGOC. For around Â£15 this kit has two relays (one for main, one for dip beam), with all the wiring hooked up (including a fused spade connection to hook up to the fuse box) and even has all the connectors. All you need to do is find somewhere near the fusebox to mount the relays, feed 4 wires through to where the headlight bullet connectors sit under the slam panel behind the grille.
The good thing about this kit is that it is a non-destructive fit, meaning that you can easily put everything back to stock as no cutting of original wires is required, all you are doing is changing where bullet connectors fit.
The trick to fitting this kit is not to assume that the single wire going into the headlight bullet connectors (and coming out of the other side as two wires, one to each headlight) is the powered one! I made this assumption and was left scratching my head as to why only one light was working. Find out which wire is powered for each of the circuits in advance and this is a 20 minute fit, start to finish. You will spend more time getting the grille off, cleaning off the headlight wiring (so you can identify colours), and finding somewhere to fit the relays than doing the actual wiring.
And the result? Well I used the B last night for an hour in the dark and I can say it was money well spent, the road is finally properly lit!