Checked my Crosstar.
Back Seats Up
It's 65 cm from seat back to the edge of the boot lock shroud (which is the longest point).
However, as you'll see from the attached photo, this shortens to 59cm on each side of the shroud, as it curves inwards.
Then, factoring in both the seat and tailgate incline, the measurement of 59cm goes significantly down if measured from the top of the rear bench (to approx. 39cm-45cm).
Back Seats Down
150cm from the boot lock shroud to the back of the driver's / passenger's seat (in normal driving position - aligned with the back of the centre console where the USB ports are).
As these have fabric backs, there's a bit of give, so you can get an extra 4-5cm on top of that. Or more if you move the passenger seat forward.
I couldn't check the front seat yet as it's parked up next to a wall currently. But I think it's a no (from what I can remember).