Disabled car rollers

[John A. Heer]

Folks:

I have decided to stop selling parts off my wrecked SE-R and have a
junkyard tow it away.

One problem is that the car is immobile because I took off most of what
enables it to roll (no wheels, no struts, no springs).

Another problem is where the car is situated in my friend's driveway,
making it almost impossible to get a flatbed back there to winch it onto
the bed.

So, I looked into those steel rollers you can use to move cars which
have wheels and tires, but they are $179 each!!  I was thinking of
making my own out of layered plywood and heavy-duty casters.  I was
thinking of double layer of 3/4 inch plywood in 4 squares with four HD
casters on each square.  They would be placed at the jacking points of
the car fore and aft of the wheel wells.

My questions:
1) what size should the squares be - one foot square or less?

2) will this be sufficient to support a shelled-out car in order to move
it down a 50-foot driveway?

The car has no engine, no tranny, no trunk lid, no seats and no
suspension to speak of.

Thanks.

John Heer
93 SE-R not stock
And one shell of SE-R