Alright, after spending about an hour on the TX DOT website i could only find this:
ยง 503.069. DISPLAY OF LICENSE PLATES AND TAGS. (a) A
license plate, other than an in-transit license plate, or a
temporary cardboard tag issued under this chapter shall be
displayed in accordance with board rules.
(b) A drive-a-way operator who has been issued a drive-a-way
in-transit license shall display the operator's in-transit license
plates on each transported motor vehicle from the vehicle's point
of origin to its point of destination in this state in accordance
with the laws relating to the operation of a vehicle on a public
highway.
Now as you can see it states nothing of relavence so i called the local police department and after talking to 5 different officers who didnt know the law i finally reached one who told me that the law only states that the plates have to be mounted on the furthest most point of the front and rear of the vehicle and that the rear plate needs to be lit. He went on to tell me that if the plate is mounted in any position on the rear of the vehicle so that it is visible from the rear of the vehicle that the judge will usually alow that.
I dont really trust that explanation because imo it depends alot of the officer and the judge so its probably alot safer to just mount it to the rear rollpan or tailgate but i think im going to take my chances above the front of the bed and see what happens. I think an old Chevy truck will get more leadway than a new ricer from most cops and judges.
I think its pretty sad though that i had to call the dps the tax office and 6 different police officers before i could find someone who knew the display laws and even then the cop was stating his interpratation of the law rather than the facts of it.