chimaera

I wonder if it's the steering angle sensor? A diagnostic scan would help at this point.

With a remap, the ECU does know exactly what's going on with the sensors and control things properly. The tuner will make sure the engine stays within its limits, unlike a tuning box which won't. But go ahead, it's your money you're throwing away. I'm only an engineer, what would I know eh?

Your opinion is wrong sunshine. If the ECU is getting incorrect data it is not under control. What tuning boxes do is modify the signal sent back by a sensor so that the engine thinks it's reading out lower than it actually is e.g. when the MAP sensor is actually at 0.8 bar, the tuning box fools the engine into thinking it's only seeing 0.6 bar, so it'll overboost by 0.2 bar. When the ECU hits its limit based on the reading it's getting from the tuning box, it is in reality 0.2 bar above that limit and in dangerous territory. Same goes for fuel rail pressure. Some of the more expensive boxes have tweaking to reduce the offset near the limit but it's still a bad job. You're now suffering from choice supportive bias: you've bought so heavily into these stupid things that you're unable to accept that they might be a whole lot of nonsense.

I guess you didn't read the other thread then? The ECU is no longer fully in control of the engine if it's being fed bad data from a tuning box. And all any tuning boxes are capable of doing is feeding bad data to the ECU so it overfuels and overboosts. If you want more power get a remap from a reputable tuner.

They're a bad job. End of story.

You've almost got it back together right in your pics, but there's a little spring missing. You can just about see it on the side of this pic from my install:

This is all information that you should have posted in the OP. If the ECU doesn't know what the methanol kit is doing, it's dangerous as the engine is effectively out of control. This is also a question that should be put to your tuner rather than asking here, as the tuner (assuming they're competent and familiar with what you're trying to do) is going to have a better idea of how to do this. If the tuner has already suggested that this is a bad idea, it would be a good idea to listen to them.

Yes - your dealer should be able to get them for you.

Michelin CrossClimate+ - fit a set of 4 if you can.

If it's standalone then how is it advancing the timing (your original question of how to retard the timing in the event of a problem suggests that something is advancing the timing when this kit is active)? TBH I think putting methanol into the engine without remapping/replacing the ECU to control it is looking for trouble.

Surely the remap needed to make this setup work would have that built in?

If it's anything like I did, probably prising off the cover of the switch module instead of prising the module itself out of the housing when removing it to fit the microphone.

I use Chemical Guys Diablo Gel, or CarPro IronX for bad fallout stains. Avoid anything acid-based.

You'll need a remap.

The Superb 2 had different wheel caps before and after the facelift. The earlier ones tended to look crap after a while but the newer style seem to last better.

Which version of the Skoda ones have you tried, facelift or pre-facelift? Also, what problems have you had with them?

UK importer specifies every 4 years or 100000 miles. Skoda CZ says at 210000 km without a time limit.

When it comes to suspension, 2 cm is a huge amount. On the front axle it's going to make the steering really odd, on the rear it's probably just going to shred your tyres because the geometry is a mess. They are sold because there are lots of people in the world with more money than sense who think they're a great idea. The only remotely good reason to use the is to fit wheels with a different offset but for that it's better to buy wheels with the correct offset in the first place. And it's not just you that's at risk here, it's anyone else traveling in your car or sharing the road with you. This report goes into the finer points of suspension design and might show you why what you want to do is a bad idea: https://www.semanticscholar.org/paper/Design-of-a-Suspension-for-a-Formula-Student-Race-Theander/e33489bb1ec02715530f225d40c0e4da6b451856

If they're the original wheels, fitting spacers is going to mess up the suspension/steering geometry and could leave the car dangerous to drive.

Buy wheels that fit your car instead!

I went from a fairly basic B5 Passat to the Superb 2 and the only thing that's caught me out any bit is the XDS when it tightens the line mid-corner. A few times I've had to back off the steering a fraction to stay out of the ditch.

Also consider that the DPF was designed into the engine from the start, so the turbo will have been sized with that in mind and won't have much overhead to improve if the DPF is removed.

We swapped ours for an Amundsen+ RNS-315. They're around €350 on eBay. Almost plug and play, just a bit of cable routing work needed for the GPS antenna and microphone (for Bluetooth).

These things tend to be fairly specific, most likely to the chassis/platform. Have a look at other cars on the PQ35/PQ46 platforms in the VAG group brands.

Superb 1 has a completely different platform compared to the mk2. Longitudinal (rather than transverse) engine mounting which was designed to accommodate the Audi V8 engines for the A6. The engine bay in the mk2 started life in the Golf mk5 and is a good deal smaller.