I’d be interested to know what makes you think the dealer who delivered your brand-new car has changed the tyres. Were they showing signs of wear? Did they make the car handle or ride strangely? Did they just not look 'right’?

I can’t imagine any dealership would be stupid enough to fit partly worn tyres on a brand-new car. You bought a new car, it should come with new tyres. Simple as that, and anything else is pretty shifty to say the least. The dealer might have switched to another set of brand-new tyres if one or more of the originals was damaged, but that’s not what you’ve suggested here. I’d definitely be taking it up with Nissan Australia’s customer service division as selling a brand-new car with second-hand tyres just seems crazy. Not to mention legally questionable.

If it’s simply the case that the tyres’ tread didn’t look brand-new, then the 26km it’s already covered could explain that by taking the shine off the tread. That, and the fact that the sidewalls were probably still very shiny (dealerships love tyre-shine products) could make the treads look worn when they really weren’t.

The faulty tyre-pressure monitoring system is a separate issue and can be fixed by replacing the dud parts. This is a simple warranty claim, and even though tyres are generally not covered in a new-car warranty, selling a brand-new car without brand-new tyres is a new one for me. If it really did happen, you’d be well within your rights to demand brand-new tyres.

This model X-Trail is fitted with active lane-keeping assistance which is sort of a helping hand when the driver isn’t keeping the car in the centre of its lane. It could be that this system is what’s causing the car to feel like it wants to pull you into the next lane.

You need to have this checked under warranty as soon as possible, since it’s an obvious safety issue. This isn’t just a Nissan thing, either. Many brands have had complaints about these systems, and in some cases, cars fitted with collision-avoidance systems have been known to slam on the brakes when the car’s camera 'sees' something like a wheelie-bin on the footpath and mistakes it for a truck entering the road. Speaking of which, your lane-keeping assistance is controlled by a camera at the front of the car. Have a quick check to make sure there’s not a huge dead bug confusing the camera.