If neither the key nor the central locking will lock the hard-tonneau, it’s likely the latch is not engaging properly. Which in turn means you most likely have an alignment problem between the tonneau and the rest of the tray.

I’m not sure if you have the factory tonneau (probably) or an aftermarket one, but these are big, fibreglass panels that can sometimes shift a little on their hinges and fixing points, leading to the misalignment that won’t allow the latches to line up and engage.

The factory HSV tonneau for this car has a quick-release hinging system allowing it to be removed easily for carrying higher loads. Perhaps removing and refitting the tonneau via this feature will return everything to its correct alignment.

Noises like this are mostly temporary and are caused by a small rock or some other foreign object becoming jammed between the brake disc and the brake pad. Often, a sharp jab of the brake pedal (when it’s safe to do so) will dislodge the object and peace will be restored.

But if you’ve replaced the wheel bearings, then you’ve already had to remove the brakes. So unless the stone or whatever is lodged deep in the brake pad material, that’s probably not the cause here. Which means you need to look more closely.

The ABS sensor is an interesting theory, but I’d imagine if the clip had broken and dived into the front end anywhere, you’d have an ABS warning light on the dashboard by now. Perhaps it’s something to do with the front hub or the front driveshaft assembly. Perhaps a CV joint? Check for damage to the CV joints’ rubber boots. Don’t rule out a pothole having wrecked your wheel alignment, at which point what you’re hearing is a front tyre being torn to shred.

And what about the power steering system. These can squeal when they’re low on fluid, have air in the system, the belt is slipping or the pump itself is worn out.

The trick to a diagnosis here might be to find out what rotational bits and pieces are involved. To do that, you need to work out whether the noise is wheel-speed related, driveshaft-related or engine and transmission-related. The driveshaft spins fastest, followed by the driveshafts and finally the wheels, axles and brakes. So that’s probably the key to it.

Even something as simple as a bent or loose brake shield can cause a rattle, squeak or grinding noise, and some owners have gone so far as to strap GoPro cameras under the car and take it for a drive to see what’s going on. A mechanical workshop will probably be a bit more scientific, but the basics of troubleshooting remain the same.

As far as the driveline locking for a moment, you could be looking at a related problem or a completely separate issue. It’s probably wise to make sure the transfer case isn’t suddenly shifting into neutral or low-range on its own for that split-second, as that could cause driveline chaos. But a sticking brake caliper or faulty ABS module could potentially also cause the same sensation.

Some cars cycle their ABS systems when you first start up and take off, and this can lead to a metallic noise for a second or two and a slight buzz through the car. It can be intermittent, too. Are you sure that’s not what you’re hearing?