Stewal

Clutch and brake pedal switches are a good place to start. Then scan with a code reader: traction control, eml, abs faults etc usually disable cruise but would expect a dash warning light too......

I have had this a few times recently particularly if it's been hot with the roof closed. In my case the bottom edge of the roof where it sits on the bodywork at the rear lid had stuck to it (there is a clear plastic strip that it sits on). The crud that had accumulated on the strip was sticking the roof to the lid stopping the opening sequence. I eased it gently up whilst operating the button and cleaned and polished the lid and it's been fine since.

Looking at your picture I guess someone has deleted the reverse light in the bumper and made it a second fog light? I would look at how that has been done and maybe disconnect to see if it changes anything. Leds in fittings not designed for them can create all kind of funnies. Maybe revert to standard bulbs to see if the problem goes away. I do find you get what you pay for with leds. I only have them for the front sidelights and used Philips units which have been no trouble.

I wonder if the difference is roadster v coupe as the windows drop for the roof operation.

Are you sure it's supposed to auto up on the passenger side: mine doesn't. It's auto down both sides auto up drivers only. Ah forget that: just misunderstood op!

When you drain the oil you never get it all out: so when you first swapped to w40 grade you already mixed it a little bit with whatever was in there before.......no issues.

Road tax bands is another factor that plays with buyers these days. The numerous bands and rates are a complete mess particularly for newer cars. I know someone who unknowingly got stung for the 'luxury' car surcharge on road tax even though it was several years old. I guess yours will be in the higher post 2006 bracket but even my pre 06 car is nearly £350 these days. Those of us who appreciate bigger engined motors will pay it regardless if we can, but I do feel we are a dying breed that will get spanked in every budget!

I believe the standard sender unit operates both the gauge and warning light, so I suspect if you reconnect the original gauge pod the warning light would work. You would need to get a look at a wiring diagram to confirm this and see if its possible to fool the car into thinking the gauges are still there in order to get the light working.

After a track blast things like the yaw sensor will have been thrown about a bit. On some cars a spurious fault indication takes 5 or 6 cold/hot engine cycles to reset, if not, then I would get the obd read by a more sophisticated reader.

As said, best get the codes read but when I had this it was a camshaft sensor. If it is, it's an easy fix, but don't buy cheap Chinese ebay copies!

I doubt there will be any bulbs in there: they will likely be led's, which won't be a 'service' item but should outlive the car!

Assuming the oil is good and the level correct, I would say confirm the readings with a manual gauge: the senders do fail and should only be replaced with an oem standard one: ebay Chinese copies will be cheap but unreliable. With ac off that idle speed sounds right: put the ac on and the idle speed and oil pressure will increase.

14psi. Bear in mind the A/C raises the idle a bit so pressure would indicate slightly more if its running.

Does the 370 have the manual overide switch to operate them (lights have to be on) like the 350 does?

On many cars which share the same reservoir the light washers trip long before the bottle is empty to avoid having nothing for the screen. So it is certainly wise to test with a full reservoir before assuming a fault.