dr_mat

There is no OE anti theft module, there is only an optional unit that was dealer-fit ("Cobra" branded I think). This is not factory integration it's about as reliable as any other after market bodge. Personally I would have it removed, or remove it myself. Unless it's different in North American cars I can't see it being any use in the modern market anyway as it's lost its insurance rating a long time ago.

If you have vagcom/obdeleven/vcds you can read off from the ECU whether start was allowed or not by the built in immobilizer. For what it's worth, iirc failures with this usually mean the car fires but won't run for more than a second or so. Coincidentally having one of the above diags tools will allow you to find what's really wrong with it... Sounds like your aftermarket immobilizer is preventing start to me.

I thought it was the push switch in the rear hatch. (The one that came loose and fell inside.......!!!)

Anyone know of any scanning facilities?

Well that's very random.

Re the NOS falling apart too .. This doesn't surprise me. We really need someone to get some 3D scans done and open source these parts.

I know, right? Quicker, AND more reliable!

Sounds like a carcoat damphands piece, lol. I take exception to the description of the pictured car as "unmodified", sitting as it does at least 30mm lower than a standard car, if not 50mm... A fun write up though. :)

The future of most corrados is undoubtedly electric traction motor from an e-golf...

I'm sure I found them selling a headlamp for a late car at one point, but it's not listed any more. 60 Euro. Ouch. But yeah, they are rare and unique ... !

Yes it's a problem .. you can buy new old stock headlights, but I've only ever found one side. https://www.vwheritage.com/536941018-headlight-for-right-hand-drive-right-vw-spare I fabricated something: http://the-corrado.net/showthread.php?108656-Headlights-still-poor

Relieved to say "404 page not found"..!

Serious engineering work there. I'm sure VW could design it..

These don't look big enough to me. It needs to be about 30mm diameter.

The knurled knob is a bit weak, but that's no big deal, it's the large plastic grommit type part that engages into the rear of the headlamp housing and has the screw thread through the middle of that breaks. You don't need to touch the adjuster to remove the lens, but it's very hard to put so little pressure on the adjuster that you get the reflector out without breaking it, it's phenomenally fragile. 3D printed replacements would be GREAT. If you can find an undamaged one to copy .. !!!

I don't think it matters where you route the cables as long as they are not pinched and still free to move.

Yes, loom and bulbs will buy you lots of lumens but it's still going to look bad (and fail MOTs) if the reflectors are useless. I used Dual Metallising last year, they provide a great service with really amazing results. The issue you will have however is that the adjuster screw mechanism will collapse due to the crappy non-heat-stable plastics if you're not ultra-ultra- careful when removing the reflector from its retaining ball-and-socket mount points behind the reflector. I trashed both of mine and wound up fabricating something out of some similar (but smaller) parts off a Scirocco headlamp (still available for a couple of quid), and some large penny washers and self-locking nuts. It's a pain to adjust now ..

But they do WORK. For a while, at least. I do suspect you have other problems. There's Hella ones on ebay for ~£130 too.

Not a bad price here, but no clue if/when they are likely to come back in stock. https://www.vwheritage.com/021905106-ignition-coil-vr6-vw-spare Otherwise I usually find at least a couple on ebay from a 1990's VW VR6 of some description.

Useful info: https://www.wheel-size.com/size/volkswagen/corrado/1995/

The coil pack has only three coils, so each vertical pair of outlets should spark at the same time. Sounds like you have a DOA Topran coil pack to me. EDIT - if you have the same issue with two coil packs it does seem more likely that you might have an issue with the HT trigger output on the ECU. The coil packs are simple, they usually fail because of heat cycling so even a new old stock one is unlikely to be faulty. As per the grouping on the coil pack itself the ECU has three output trigger lines. I don't know which pins those are but that would be where to look next I would say.

I thought they were officially obsolete, but maybe I was thinking of the brake master cylinder? Cor, I even said this in the thread you linked above too!! I should get out more!

I think the original lenses were hardened and tempered, but heat shock is heat shock, they all go eventually. Anyone have any suggestions for good legal (ish) warm-white (i.e. unobtrusive) LEDs to replace them with?

It would be linear, so IF the two speedos are differently calibrated (I can't see why they would be), you would be able to linearly scale the pulses from input to output side. However, I would only expect the two speedo binnacles to require different calibration if they were intended for cars with different final drive, but AFAIK that's not the case, AFAIK all Corrado VR6/SLC had the same final drive ratio, and the same wheel sizes, so the speed signal should be the same, and the dash calibration should be the same. And 4-5mph out of actually pretty close.. factory calibrated gear is rarely any closer than that, they always over-read by a comfortable 5-8%.

Dunno, but the wheel speed sensor still depends on wheel and tyre size so you need to calibrate for that. Gearbox feed has the exact same problem, you just need a different calibration because it also goes through final drive and the diff. Personally I'd keep the ABS working with 700 bhp in a Corrado, given a choice!