Stewal

This is the link. It seems the red led on the dash top is the key. https://youtu.be/YHJ8JQKtdtE I would also check the fuel pump and ignition relays and the microswitch on the clutch pedal.

Next time it fails to start, lock and unlock with the fob. It could be the immobliser, there is a US video of this on you Tube.

Having fitted really useful reversing sensors to my 05 convertible I find the sounder in the boot is too faint, presumably because the roof area is insulating the sound from the cabin. Is there an easy route to pass cables from the boot into either the cabin or the roof stowage area using existing grommets rather than drilling. Cheers.

I can fully concur with my experience. my 2005 Z has only every needed servicing and a cam sensor. I bought a 2005 mk1 V6 TT quattro with similar mileage for a bit of winter fun but its so fragile compared to the Z with several niggles which would be ludicrously expensive to fix. Its woefully underbraked compaed to the Z and should it be the servo then unbelievably the engine has to come out and it will suck up about £1600! The rear ABS sensor which needs doing, can't be done without removing the disc and caliper and even then its likely to be seized into the hub requiring a whole new assembly. Glad I kept the Z alongside it and having had a similarly good experience with a mk1 MX5 which just shrugged off anything I chucked at it, I think staying Japanese is the answer for me.

I wouldn't be at all surprised if this was tyres or a wheel issue. Particularly as you say they are worn. If the tyre size allows it, maybe try swapping fronts to back and see what happens. I had very similar with a previous car: sounded for all the world like an intermitent wheel bearing issue but it was the tyres.

When you read the fault codes my guess would be a camshaft sensor. A fault in these produced just the symptoms you have in my own car. Easy diy fix.

Would certainly endorse Alex's point about oem for the sender. With some parts its buy cheap pay 2 or 3 times over.......I speak from experience! Even a good used oem part will be better than a cheap ebay chinese copy.

Almost certainly the sender unit which is easily accessible to change and not too expensive - do not over tighten though.

One of the most basic checks you can do and easiest fixes is to check the fabric straps above your head, one on each side. They need to be tight enough to pull the front part of the frame. Over time they loose their strength and become floppy. Check youtube for some easy fixes using bungey cord and similar. I believe they can be bought as a service item but the roof fabric has to come off to rivet them in. Thats why many resort to elasticated cord which seems to do the job.

From my own experience with a standard low mileage car and original fans(2006) the drivers side does most of the work, coming on with ac and normal idling temps as required but get the car hot enough and both come on. Try giving it a bit of a spanking then let it idle until fans cut in, it will probbly trigger one then,soon after, the second. On mine, putting the ac on at these higher temps puts both fans on straight away. At least thats how it works on mine without any issues over many years, iincluding an annual trip to the Italian/Austrian passes in summer heat. its very confusing trying to fathom out the correct behaviour online because so much of the internet info is US based, and from what I can gather, the Mishimoto replacements don't follow the original pattern, but put both fans on at high speed in all circumstances.

As far as i remember there is only one crank sensor and a camshaft sensor for each bank. Each has their own fault code so unless you are getting other codes I can't see it being anything other than the throttle body its telling you.