Ive seen a number of vehicles with the lettering going like a black oxidised smudges over the letters does anyone know what this is or is a cleaning product interacting with the letters?

There is a service bulletin about this is you do a search you’ll find people talking about it and I believed dependant on the age of the car you can get the dealer to replace, but it has to be pretty new.

I got a set of replacements from powerful UK and they are much nicer, see picture of old and new whilst fitting on mine.

As fin says, a common, known fault.

I posted a couple of weeks ago about this and the Powerful UK replacement letters which were ⅓ of the LR price, seem good quality are are straightforward to fit.

There’s a Powerful video on YouTube to help get it right.