The first thing to figure out is what type of smoke it is; oil smoke or fuel smoke. If the smoke is black, then it’s probably excess fuel that is being injected into the engine. If the smoke is a bluish-grey, then it’s likely to be oil smoke. The major causes of oil smoke are worn piston rings or valve guides and their seals. If it’s either of those thing, it will be a fairly major repair bill.

But it would also be worth checking the crankcase ventilation system as this can cause an engine to smoke, too, and is a much simpler fix.

This is a really interesting question, because most car-makers tend to quote their products’ luggage capacity in litres, rather than a set of dimensions in each direction. Even then, it’s not that simple as there are different methods fort calculating the cubic capacity of a load space, and the two methods are not readily comparable. It’s also a bit of a con-job, because a figure in litres mean very little to most people, while actual measurements in centimetres would be much more relatable.

In any case, since you obviously have two kids with cellos and school-bags, it’s clear that you’ll also need the rear seat for at least one passenger, so you need to find a vehicle that either has enough space in the rear with the first two rows of seats in place, or a car that has a split-fold rear seat to allow longer loads (like a cello or two) to pass from the luggage area into the rear seat space. The good news there is that many (if not all) SUVs do, in fact, have this split-fold seat, and that will surely accommodate even a full-sized cello which, after a bit of scratching around, I discovered is about 121cm long.

If, however, you need to occupy the whole rear seat with passengers, then you need to find an SUV that is wide enough to accept the cellos loaded across (or diagonally across) the car. That won’t be easy, because most vehicles just aren’t that wide inside. Even a conventional full-sized car-based Holden or Ford utility (which aren’t being made any longer) is only about 1400mm wide. And if you check out something like a Hyundai Santa Fe, it’s load area with the third row is feats down is just 1080mm at its narrowest point. Even the huge Hyundai Palisade is just 1111mm across the narrowest point of its load area. There will be areas where the space is wider, but that narrowest point is usually between the rear wheel-arches.

I’ll also take a punt and suggest that the cellos in question are either in carry-bags or even hard-cases which would add even more to their length. So you might find it very difficult to find anything that will accommodate a 1.2 or 1.3 metre cello lengthways in the luggage area without resorting to folding down half the second-row seat. Even a big car like a Volvo XC90 has just 1220mm of load length with the rear seat in place, and mid-sized station-wagons typically have less than a metre between the tailgate and the rear seat. The best idea might be to make a short-list of cars you’d be happy with and then visit the relevant showrooms with a tape measure (or even a cello) in your hand.

There are many variables that can determine how reliable or or otherwise a vehicle can be, especially one that's 11-years-old. A full Volvo dealer-stamped service history, careful owners and pure luck all play a role here, and should be a prerequisite. 

Research shows that the XC90's D5 diesel engine's injectors have been known to fail, and this can be an expensive fix. This may or not be associated with power-loss issues.

Blown turbos, electrical faults and overheating problems have also been reported multiple times.

Some earlier XC90s have been known to suffer from complete transmission failure, reportedly preceded by "strange" noises before bringing the car to a total stop. It seems regular full transmission servicing really reduces the instances of this happening, so again, insist on a fully-stamped service book from authorised Volvo dealers or specialists. 

While not strictly speaking mechanical, the Volvo's sunroof can leak, and this can become very costly to rectify. Neglecting this problem can then lead to electrical failures and water ingress damage inside the cabin.

Our research shows the XC90 D5 of your vintage is no more likely to break down than most European rival luxury SUVs of the same period, which is reasonably good news, though Japanese alternatives do perform better generally.

We hope this helps.