Yep, I’m replacing mine because loads of the orange paint has flaked off. I’m surprised it passed the MOT because they’re not very orange any more. I tried a PY21W LED that claimed to be “canbus compatible”, but it raised a bulb failure warning. It was fine on hazards, but with ignition on and signalling, the error occurred immediately. Perhaps the bulb-checking only happens with the ignition on. It was also a little too bright for night-time use. So I tried another one off eBay: https://www.ebay.co.uk/itm/374844629873?var=643919891661 I received the second one today and it appears to work, and is a little less bright. I’ll have another look when it’s dark. The PY21W retrofit LEDs are generally slimmer and do fit through the hole. I don’t think I’ve ever come across any other car that uses RY10W indicators; they seem more common on bikes. I did find a thread elsewhere on Briskoda about the front indicators, and that did mention a Torx T20 screw securing the base of the bulb. The thread implied that the screw is just about accessible, and only needs loosening. Easier on the left side, apparently. The front indicators are my next target for retrofitting LEDs. I think it’s fine to have brighter ones on the front because at night they’re competing with the brightness of your headlights and therefore unlikely to cause dazzle. I believe the correct type is PH24WY, but I haven’t confirmed that yet. My experience is that “canbus compatible” is no guarantee that a bulb will work, but it’s worth persevering and you may well find one that does. By the way, before someone tells me that the bulb checking is nothing to do with the canbus per se, yes I know that. But rightly or wrongly the phrase “canbus compatible” has become lingua franca when discussing retrofit LEDs. Technically wrong, but it’s the phrase everyone uses.