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.
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.
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.
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.
Thanks for the tip, but mine is so bad you take the sag out of one area and it reappears somewhere else. It's got the rigidity of cardboard!
It's either an expensive metal replacement or nothing and I think I will do what Alex suggested and try running without.
Cheers.