The short answer: no
The longer answer -- a while ago, prospero pointed out you could find pitch and bank information by comparing various points on the vehicle and doing some trig transformations.
Basically, you get the vehicle's position, then you read the position of say the driver. You can use those points plus the other info (getdir of the vehicle) to figure out the orientation of the vehicle. Then, if the turret is off-axis, you might be able to getpos the guy in the turret, and figure out which way it's pointing.
But I doubt it'll work