I'm looking for opinions or experiences with LED bulbs or LED conversions for a 2008 TDV8...

I don't want to mess up the system with error messages etc, but if there's a decent conversion kit or some good bulbs that could improve the lighting and look of the car, I'd be keen to know about it!

With headlamps you will need to replace the whole unit not just the bulb as it’s now an MOT failure to have LEDs in a unit not designed for them. For things like puddle lights etc you’re fine. For fog lights I’ve found that LEDs aren’t as effective as halogen but they are good for indicators (orange for clear indicators). 2012 5.0 SC AB
Mods:
TPMS
Genuine LR DRLs
Remote Boot close from key fob
2016 Discovery 4 Mirrors AKA RRS2
2014 L405 Surround Camera retro fit (WIP)
2013 RRS Dual View Screen fit (Complete)
2016 LR4 RSE
2014 LR4 Homelink
2016 FFRR Electrochromatic Wing Mirror Glass

70 plate Focus ST (Current)
1942 VEP Ford GPW Jeep (Willys) (Current)
1943 Whites M16 Halftrack (Current)
16 plate Eurofighter Typhoon, 2 x Eurojet engines with 20,000lbs thrust each. 1380mph

As above, it's the reflectors in the light units that are not designed for LED light spread. The light scatters, and that's what causes the dazzle for oncoming cars.
Best to change the whole unit and stay within MOT regs.

The world seems to have gone mad for the brightest possible light in headlamps at the moment. Fine while you're behind the light, but awful facing it.

The OSRAM bulbs get good remarks on the D3 forum. May be worth trying those first. Not cheap tho'. 2011 MY D4 HSE
Previously 2001 D2 TD5, 1996 D1 300Tdi, 1985 90 2.2 petrol.
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Thank you both - this forum is SO useful for advice and info.

I definitely want to stat MOT compliant, and I'm not really looking for super-dazzling lighthouse lamps... but I drive a lot of lanes and unlit roads, so I think an improvement (if possible) is a good idea.

I'm now hunting for a good replacement unit... (I'll be back soon with more questions I'm sure )

Also, PUDDLE LIGHTS... I don't seem to have them?

Just stick Osram Xenarc Nightbreakers / H7 Nightbreakers in and ensure the beams are correctly sdjusted. The original RRS TDV8 headlights are excellent with decent bulbs and correctly set up units.  2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed