HereBeBeasties

Friends of ours just had the same on their VW Tiguan when they came to visit on the weekend. If you no longer have access to the car (uncertain from your post) ask them to confirm the actual issue. Our friends had error code 10666 (P173500) which is the position sensor for clutch 1. After doing some research it seems it's possible to replace this without buying a whole new mechatronics unit, but it needs a soldering iron, so main dealers will just replace the whole thing. There's a thread about it here - https://www.briskoda.net/forums/topic/524893-mechatronics-failure-10666/ Various places like https://eco-torque.co.uk/blogs/news/dq380-dq381-dq500-bosch-versions-0bh-0bt-0dl-0de-0gc-p1735-p1736-clutch-postion claim to be able to fix these. If the whole board has failed then you'll need a whole new unit.

Don't have a Fabia, but this happened on my Superb due to a blocked sunroof drainage channel. Your alarm problems are likely due to water getting at connectors/computer module under the passenger seat. Like you, I read that it might be water ingress around the scuttle/pollen filter so: Windscreen wiper arm removal - back off the nuts at least a couple of turns, and then it's just a push-fit into the spines on the fitting - use a coin and a mole grip to push them off (add a couple of drops of penetrating oil/WD40/whatever and leave for 30 mins if this proves difficult) Scuttle cover removal - obvious fasteners on the front, but it's just a tight push-fit into the channel by the windscreen, so you can lift it. May be quite hard to lift an initial corner, but it will go. Pick whichever side is easiest to start with and work inwards from that. Mine was also a bit brittle from UV exposure as it's lived outside for ten years; take care you don't tear the plastic. Cleaned it all out as there was some blockage, but nothing sufficiently incriminating, though. Figured out it was the sunroof drains, so pulled the A-pillar trim off, disconnected at the scuttle end, cleaned them both out properly and reassembled. Drying it out: Unlikely to need to remove door seals; the plastic sill trim may sit just under the lip of them, but you can pull it off from the lower interior side of it. It's just clipped in, except perhaps around the seatbeat anchor where you may need to unclip the two sections - elsewhere just yank it pretty much straight up and it'll click out; the clips are pretty robust. You can then peel up the edge of the carpet enough to get under it properly, at which point you will discover the soundproofing under it is extremely wet, and decide you need to invest in a wet & dry vac (e.g. from Screwfix) so you can pull out what will be a proper puddle of water from underneath it all. You will then decide that no dehumidifier/vac is ever going to be able to dry out what is essentially a sponge, under a carpet, in a drainage-less tray of wetness. :-/ You will then decide you need to remove the carpet and sound-deadening underneath it and dry it all out properly So I ended up: Removing both front seats and computer under the passenger one (this will be what's causing your alarm problems, probably) - needed to buy a dedicated triple-square (XZN) bit to do this (amazon) Removed rear seat squab (mostly just clips in, need to push hard downwards to disconnect the hooks under the back of it) Detached and lifted the center console, so I could get the entire carpet and sound-proofing matting out to dry them out. This took the most time by far. All in, took a whole afternoon to figure out how to get it all apart without breaking any clips or connectors, although it went back together easily enough. Shampooing the carpet and hanging it and the soundproofing mat over a climbing frame in the summer for a few days to dry it out properly. The soundproofing matting was utterly sodden and very heavy - literally litres of water poured out of the corners when I hung it up. I am certain it would never have dried out in the car in UK weather even at the height of summer, let alone this time of year.

Stick your VIN into https://updateportal.skoda-auto.com and you'll be able to download it. I'll be around 16GB zipped, which will expand to ~22GB unzipped, so you'll need a 32GB+ USB stick or SD card (both SDHC and SDXC is supported).

FWIW I have just replaced the rear springs on my 2015 Superb 280 L&K estate with DCC but no tow bar with Eibach R21706 items. There is a marked improvement to the ride and control of the rear in all DCC modes - the previous floatiness is gone and it doesn't feel too stiff/brittle, even unladen in DCC sport. The distance from rear wheel center to arch bodywork is 39cm when unladen with half a tank of fuel (cf. 38cm at the front, on the original springs at 65k miles). YMMV, etc., but I suspect you'd be happy with a set of those, given I am on a non-towbar car without the LPG tank.

I've just replaced the standard rear springs on my 2015 Superb 280 DCC-equipped estate with Eibach R21706 items, as one of the originals cracked all the way through and I figured I may as well try some slightly stiffer springs than stock in an effort to quell the boat-like rear. It's a considerable improvement on the original springs IMO. I was a bit worried that going up a whole 1mm from the original 12.5mm spec to 13.5mm spring thickness would be a bit much (the new ones should in theory be 36% stiffer), but it now feels really good to me. NB: You may well want less stiff ones on a non-4x4 / non-estate model with less weight over the rear.