Can anyone point to high output low wattace LED bulbs that fit car rear light fittings - they would be very useful in a caravan.

LED rear lights are widely used on US autos, but I haven't seen "bulbs" that can be used as direct replacements for original incandescant bulbs. The most common use is for the "high mounted brake light" mandated a few years ago. Typical assemblies use 30 or more individual LED "lenses" and replacement is specified when something like 30% of the individual lens elements burn out. (It appears that nobody ever actually replaces one.)

Casual observation (from the number of missing dots on vehicles ahead in traffic) suggests that about half of cars 4 or more years old should have their light units replaced, so the "forever" life claims are unrealistic.

On my 1975 Astro, worn out and discarded about a year ago, a replacement "top tail/brake light" had a list price of approximately $198 (US), and the only way to fix one was by replacement of the entire unit. So far as I found, there are no "after market" suppliers, as demand is low, so only OEM units specific to the particular vehicle are generally available.

There are a few "LED marker lights" on display at nearby truck stops, and both red and yellow units are to be found. The entire "unit" must be replaced, not just a "bulb," and although the "marker light" mounting is fairly generic, lens/unit shapes do vary some so it may be difficult to exactly match a set installed at a first conversion to LEDs when one or a few need replacement. I haven't noticed any with the dual taillight/brakelight function.

Achieving the lumen output mandated for brake lights generally requires a minimum of 20 or more individual LEDs in the unit, and the customary side/rear marker size and form factor limits these units to about 9 elements.

John