Screwfix sell them £4.99 for pack of 10, and they also sell No Nonsense 2-Part Epoxy Adhesive Tubes Opaque 30ml £4.49
All stocked up, just waiting for recent hand surgery to heal and stitches out  2018 SE SDV8 4.4 Byron Blue

I have obtained some brass inserts to the same design and size as those mentioned.

As a precaution I checked compatibility of the different metals, it appears that brass in most applications is fine with steel, it is not with carbon or stainless steel in a wet environment, I also noted that mild steel and stainless steel are not compatible in a wet environment, the differential is likely to increase the speed of corrosion in the mild steel component.

I guess the epoxy will possibly insulate the two components from each other

Does anyone know what metal is used in the sunroof drains?

I have obtained some brass inserts to the same design and size as those mentioned.

As a precaution I checked compatibility of the different metals, it appears that brass in most applications is fine with steel, it is not with carbon or stainless steel in a wet environment, I also noted that mild steel and stainless steel are not compatible in a wet environment, the differential is likely to increase the speed of corrosion in the mild steel component.

I guess the epoxy will possibly insulate the two components from each other

Does anyone know what metal is used in the sunroof drains?

I'm not entirely sure about using brass and steel together—refer to the table below for more details. Brass sleeves are readily available in various sizes, but from what I've read, they're not recommended. That’s why I opted for the Wavin inserts instead.

Click image to enlarge

Have just completed the same modification to a friends 2018 405, his were a little worse than mine but still pretty solid overall. Treatment with rust converter, numerous coats, surrounded inserts with high pressure flexible sealant to avoid any change of cracking and thoroughly tested today after allowing 24 hours to cure. I am getting the hang of doing these sunroof drains but I hope I never have to do a 'proper' drill out and refit job!  _______________________________________________

2019 4.4 V8 Diesel Range Rover Autobiography, Byron Blue

I've just checked this on my 2017 model - one side was fine and the other was clearly in the need of some attention. It is very easy to remove the trim to gain access to the drain holes - open the sunroof and then gently but firmly pull up and outwards on the trim. I started at the front as it was easier to get a hand hold. Putting the trim back is also straight forward. Line it up and then a tap with the side of the palm gets it back in place.

Click image to enlarge

Click image to enlarge

I just checked mine on my 2014 SC. I noticed that when I drove off with my window open, water drops were coming in from above.

I took off the plastic strip along the side of the sunroof and the drain was crusted over with muck. I cleaned it all out and luckily no visible corrosion. Same on both sides.

Did not take long and worth a regular check. 2014 5.0 Supercharged Autobiography & 2015 3.0SDV6 HSE Lux Discovery 4
2005 4.2 Supercharged Vogue SE & 2011 3.0SDV6 HSE Discovery 4
2002 4.4 Vogue
2000 4.6 Vogue
2010 Freelander 2 TD4 HSE
2009 Freelander 2 TD4.e 2009
1992 Mercedes 300D
1986 Renault 2.1 Turbo D
1976 Morris Marina 1.8

Also worth pouring a cup of water down & confirming where it comes out.

Yes indeed, many 'cups of water invested', as well as compressed air until a healthy trickle was seen behind the rear wheel. 2014 5.0 Supercharged Autobiography & 2015 3.0SDV6 HSE Lux Discovery 4
2005 4.2 Supercharged Vogue SE & 2011 3.0SDV6 HSE Discovery 4
2002 4.4 Vogue
2000 4.6 Vogue
2010 Freelander 2 TD4 HSE
2009 Freelander 2 TD4.e 2009
1992 Mercedes 300D
1986 Renault 2.1 Turbo D
1976 Morris Marina 1.8

I Love this forum for the information and help provided have been here since 2009. Have to say, I've got a 2017 (67) SVAutobiography, and I'm really tempted to just sell it. it's not as classy as my L322, and Jaguar (Tata) have given up. They seem to be garbage build quality. It's like a 50% Range Rover, I'm sure they had to enshittify the proper Range to pretend a Sport (Discovery in Drag) or an Evoque (Freelander for the overpaid Metropolitan "Elite" ) are "Range Rovers" I'm just depressed and stressed waiting what what is going to the bed prematurely because accountants with the taste of someone who likes Dubai builds these damn things now. Am I way off? Am I in any way wrong, or should I jump ship? Formerly happymadison1978

I would have thought it’s not a good idea to leave any corrosion in place?

Surely the only sensible remedy is to totally remove any rust to bare metal, and go from there?

I’m a bit shocked at what people think is acceptable, to be honest.

Any corrosion left in situ will only later come back to bite you in the proverbial, surely? V6 Vogue - “Less is More” - less to go wrong!

I guess it depends on the cause of the corrosion & the effort to 'totally remove to bare metal'.

Some 80/20 rule has to come into play IMHO. If the corrosion was caused by a historic blockage that isn't likely to happen again...... Is this likely to be what causes my car to be finally written off ?

It's somewhat similar to - more men die with prostate cancer than because of it. It's not automatically worth treating if you're old enough & have other ailments.

I guess you could remove the headlining and spend a day or more on it, but for most, some rust eater & an insert epoxied into place is likely to be sufficient to see the vehicle to its end of life from a more serious cause IMHO