Spotted Test mules, but of what???

[The Stylist]

If the description of the unidentified car is spot-on, then it most likely sounds like hot weather testing of the new Volvo S80. There are undisguised spy pictures of this car on the internet.

If I'm correct the prototype car spotted should have a rather prominent shoulder line like other current Volvo's and the side profile will look very similar to the previous generation BMW 5-Series.