SPY PICS: Inside peek at Volvo S90

Who knows what bystanders would make of Volvo's heavily disguised pre-production S90, seen here testing in the USA and wearing Arizona plates.

Every indication is that the car is a super-secret new 5 Series BMW sedan, between the mock kidney grille at the front and the long dash-to-axle measurement. The latter is a particular puzzle, given that's how the Volvo will actually be proportioned in production form; yet the car is expected to be powered by four-cylinder engines only. 

Styling cues, under all that busy looking camouflage, will likely follow the same direction as the XC90 and recent concept cars from Volvo, including the Concept Estate from 2014 and the Concept XC Coupe. It's anticipated the S90 – a sedan – will also spawn a wagon derivative, the V90. That car may also be offered in high-riding 'Cross Country' guise.

Of some importance to Volvo fans, the spy photographers managed to get close enough for a look inside the S90, revealing the car's portrait-style HMI screen in the centre fascia and XC90-style steering wheel and controls.

The S90 will be the second Volvo to be built on the manufacturer's SPA platform, which will be shared with the XC90. While it's hard to see any visual correlation to the Tesla-rivalling model Volvo teased last week, the S90 is likely to donate its hard points and general packaging for that luxury EV, at the very least.

A replacement for the current S80 sedan, the S90 will revive a name previously appended to the last of the long-wheelbase, V6-powered sedans derived from the original 960 model, which in turn could trace its roots back to the 740/760 models of the early 1980s.

While Volvo still has some work ahead of it, based on the rampant camouflage, the new S90 is expected to make its worldwide debut early in 2016 – most likely at Detroit, as we reported back in July.