Check the regs again, it's an old law dating back to when there weren't many street lights, and when parked you were supposed to show lights on the 'road' side of the car. At one time Halfords used to sell a small light that clipped to the window, and you powered from the cigarette lighter, which showed an amber light at the front, and red at the rear.
They may have taken the law off the books, but I doubt it, if the crossfire is equipped to meet it.
I left the UK in 1995, but remember these 'useless laws' when I was a kid


Parking at night

248
You MUST NOT park on a road at night facing against the direction of the traffic flow unless in a recognised parking space.
[Laws CUR reg 101 & RVLR reg 24]
249
All vehicles MUST display parking lights when parked on a road or a lay-by on a road with a speed limit greater than 30 mph (48 km/h).
[Law RVLR reg 24]
250
Cars, goods vehicles not exceeding 1525 kg unladen weight, invalid carriages, motorcycles and pedal cycles may be parked without lights on a road (or lay-by) with a speed limit of 30 mph (48 km/h) or less if they are
· at least 10 metres (32 feet) away from any junction, close to the kerb and facing in the direction of the traffic flow
· in a recognised parking place or lay-by
Other vehicles and trailers, and all vehicles with projecting loads, MUST NOT be left on a road at night without lights.
[Laws RVLR reg 24 & CUR reg 82(7)]
251
Parking in fog. It is especially dangerous to park on the road in fog. If it is unavoidable, leave your parking lights or sidelights on.
252
Parking on hills. If you park on a hill you should
· park close to the kerb and apply the handbrake firmly
· select a forward gear and turn your steering wheel away from the kerb when facing uphill