Is it correct to use "starboard side" to refer to the "right-side" of a land vehicle (e.g. cars / trucks / lorries / motorcycles) ?
The reason that port and starboard are used in preference to left and right is to resolve ambiguity: does "right" mean on the right as I go forward, or on the right as I go aft?
(Question for the Brits and other right-side drivers out there: do your maintenance manuals refer to driver's side and passenger's side, or left and right, or port and starboard? I've never been curious about this before, but suddenly I am.)
I've never seen the terms used in relation to any land vehicle. Really they're only useful in something big enough to cause confusion between my left and steering left, so in effect ships.
Interestingly, I believe the Fleet Air Arm refer to left and right within their aircraft, versus port and starboard within the aircraft carrier. Whether this will change when they fly only from land I do not know.
Update: I find that in some military contexts regarding AFVs, port and starboard are used to reduce confusion. (e.g. 'Rifles through the starboard loopholes, aim 10 degrees left'). A few WW2 tanks had secondary turrets on each side, but these seem to have been called port/starboard and left/right indifferently. One 1940 vehicle had two forward and two aft sub-turrets, but since that was Russian (the T-35), we'll probably never know what they were called in English.