This old chestnut sorry. Not looking for a fix particularly, just curious how it actually affects the running of the car? Or is it that people like to spend a load of money purely to remove an error message? Thanks

Any thoughts?

For me, it was annoying to start with as it flashed up as an error and disappeared so quickly, you couldn't read it whilst driving so we didn't know what it was + it was accompanied by a distracting bleep. Less distracting now we know what it is - but given the root cause is well known, it's likely gonna keep doing it more and more until it goes fully open circuit. When you research this issue, in some areas (such as the US and Canada) it is a safety recall issue as follows:

"Over time, a build-up of silicate on the shift lever micro switch contacts can result in an isolationlike layer that may be interpreted as an open micro switch. This open switch normally indicates

that the shift lever is in “P” park position. If the build-up happens, it may be possible to remove the key from the ignition switch without the shift lever being in the “P” park position because the

system is unable to recognize that the vehicle is not in “P” park. This makes the vehicle noncompliant with FMVSS and CMVSS 114; Theft protection and rollaway prevention. If the ignition key is removed without the shift lever being in "P" Park position, there is a risk that the vehicle may roll away, resulting in a crash that could injure people and damage property."

Just in the last couple of months, we've had a couple of cars in our town roll down the same steep hill because the disk brakes have cooled/contracted - effectively releasing the handbrake and the owners obviously didn't leave the vehicles in gear. In the second case, the vehicle crashed through level crossing barriers at the bottom of the hill and ended up on the railway line. As auto drivers, we are a bit more protected because we have a transmission lock forced upon us.

So this gives rise to two questions:

1. Do we want a fault on our cars that in the future, might allow us to leave the car out of Park in error?

2. Is a faulty transmission lock on an auto going to cause an MOT failure? I suspect it will because it is a safety feature.