Matt Prior's tester's notes - The Volvo XC90's old, new suspension

A man, bespectacled and suited, is walking along a corridor lined with offices when he is distracted by a ringing phone.

He walks into an office, dusty and long-abandoned, finds his way over to a desk, picks up the ancient receiver and says: “Hello? No, this is [rubs dust from dial]… 4724.”

After accepting an apology, he looks around, confused, at the empty filing cabinets and sheet-covered furniture and exits, closing the door signed ‘Carlsberg Customer Complaints Dept’ behind him.

A TV ad done well. And one that a Volvo engineer reminded me of during the new Volvo XC90 launch. You know the new XC90: replaces the grey-beard one; good interior; won a group test; has a leaf spring at the back. At least, it does if it’s not one of the fancy air-sprung ones.

The last Volvo to have a leaf spring on its rear suspension was the 900 series. You’ll remember the 900, too: proper old-school family saloon and wagon; would make a great slammed drift car.

It’ll be a classic soon. It went out of production in 1998 and is an increasingly rare car now.

Rarer still is the leaf spring. But when it came to designing the back end of the latest XC90, Volvo’s engineers were keen to rediscover its merits.

A leaf spring isn’t without its positives. It doesn’t occupy much under-body room, which means there’s little intrusion into boot space. And if well designed, as a modern composite leaf spring can be, it provides a low unsprung mass.

Volvo’s engineers eventually decided, in fact, the new XC90 should have a composite one housed inside a subframe to prevent damage by road debris.

In the early stages of development, though, it’s not easy to buy a brand-new composite leaf spring until you’re really sure you’re going to want lots of them.

So Volvo’s chassis developers opted for the next best thing. They looked up the part number for the 900’s leaf spring and bought a bunch of them. And set about using and modifying them for XC90 development.

And then, I like to think, a phone rang in a distant corner of a long-abandoned office in Volvo’s Gothenburg HQ. Most likely a spreadsheet pinged in an office furnished like an Ikea outlet, but my Volvo engineer tells me the result was the same: a flag was raised over the number of important parts that were being ordered, potentially indicating a concerning trend of breakages.

They were old, well-beyond-warranty parts, on cars that went out of production 17 years ago, but it was a worrying trend for Volvo all the same.

Until, made aware of it, a development engineer explained: “No no, it was us.” The dusty handset went back on the receiver, and life carried on.