Ok, Just been stopped by the rozzers as both my number plate lights are not working, they weren't to bothered, just thought I should know. As its cold wet and rainy out, what would I be looking for first? Where would the loose connection be, as it is hightly unlikely that both bulbs have blown sine I had it MOT'd two weeks ago 07,TDV8,Black, Black Heated leather all round, Rear Entertainment with Headpones & Remote, TV, DVD, Pure Dab Digital Radio, Sidesteps, Adaptive Headlights, sunroof, now working fuel burning heater )))

The light housings aren't that water tight, so first off I'd be inclined to remove them and give all the connections are good clean and also check the wiring. Check the fuse circuit that their on too, but I doubt it's that.

Whilst you're doing this, I'd also take the opportunity to replace the bulbs with some nice shiny LED's  ON THE WAY: BMW F21 M140i
MERCEDES GL350 - Metallic Navy Blue w/Grey interior

GOING: BMW F31 335D MSport+ xDrive Touring
GONE: Land Rover Discovery 4 HSE - Stornaway Grey w/Black Interior (wish we'd kept it )
GONE: BMW F10 520D MSport - Carbon Black
GONE:MY12 RRS SDV6 HSE Sumatra/Ivory/Grand Black Privacy glass

^^^^What he says.

Cheers, will let you know what I find 07,TDV8,Black, Black Heated leather all round, Rear Entertainment with Headpones & Remote, TV, DVD, Pure Dab Digital Radio, Sidesteps, Adaptive Headlights, sunroof, now working fuel burning heater )))

i bought these and they function very well:

http://www.ebay.co.uk/itm/501-5-SMD-LED-NU...19ebbc3ac6 Recently bought a 2007 RRS HSE TDV6 for a Pimp-My-Ride-Project.
DONE: Meduza front bumper, AB rear bumper, AB tailpipes, calipers repainted, rear upper tailgate upgrade, side steps, AB front grille, AB side vents, rear LED lights, clear side repeaters, integrated daytime running lights, LED headlights.
TO DO: color code sills and pillars.

I have converted to LEDs on all internal lights, so these would be a great addition 07,TDV8,Black, Black Heated leather all round, Rear Entertainment with Headpones & Remote, TV, DVD, Pure Dab Digital Radio, Sidesteps, Adaptive Headlights, sunroof, now working fuel burning heater )))

Just a simple case of blown bulbs, not sure why both should go at once, however the casing's where wet pn the inside, so will monitor them before changing to LEDs 07,TDV8,Black, Black Heated leather all round, Rear Entertainment with Headpones & Remote, TV, DVD, Pure Dab Digital Radio, Sidesteps, Adaptive Headlights, sunroof, now working fuel burning heater )))

Quite common with those 501 bulbs, always changing them on all car side lights, total rubbish !! 2008 G4 RRSport TDV8 current
2009 TDCi 90 current
2018 Discovery 5 HSE lux current
1994 Dakar current