Antennas?

Would the pattern be towards the sky and ground?

 

I think it would only have the potential to distort the pattern at the extreme edges of the signal's travel. If the antenna were cranked down to where its entire length were just inches from the vehicle's body, the capacitance from the body would likely severely detune the antenna and foul up the transmitter's output.
But the mount position is so far aft and low on the body that there's essentially no usable vehicular metallic "ground plane" except forward. There's nothing to the rear, and hardly anything to the sides. But a whole lot of the signal is also gonna radiate off to the sides of the vehicle, at right angles to the long axis of the whips, so it would talk OK to other ground vehicles and manpack radios.
This whole array kinda looks like it's most likely to work best within a fairly short distance, like a convoy or within patrol range of a firebase or some such op. And my limited experience with this kinda gear has shown that for most operating freqs, the whip is shortened from the calculated quarter wave so it uses a "antenna tuner" (a misnomer, but we all know what they mean) at the base to dial in enough reactance so that the radios run efficiently, and at least *some* of the power makes it to the antenna and out into the ether. Even manpack radios, with the "measuring tape" short antennas, usually also come with a longer wire antenna for longer range, that can be erected once the radio is at a location where the radio op can stop long enough to toss the wire antenna over a tree or send aloft on a fibreglas pole, to get longer range.

The antenna arrangement shown is already such a compromise that I doubt that there's going to be any noticeable pattern distortion.

Either that, or something else. <-------- Handlebar's Universal Disclaimer® (Handlebar Enterprises Int'l, 1981, all rights reserved)