ok....if it is a '58 it's a later in the year one....the reflectors underneath the tail lights were a "change" for the next years model
If it is a '59(which is my guess)....the door key hole is pulled out a little from the door(like a modern day key hole)....the stiching in the seats are horizontal....the "compartment" underneath the grab handle(passenger side) is the same color as the enterior of the car
If it is a '60....the key hole is flush with the door....the stitching on the seats are vertical the grab handle have colored bars behind them
There aren't much differences in these years and you can't really tell what year it is unless you look....my suggestion is to go to the "car show" in front of McKays in Ltown and ask the guy
*handing catt a towel to sit on*