Am I going to hate this design?

[Bluedodge]

...The way the cars are in the drawing, I have 8 or 9' from the front of the cars to the wall. I figure a 3' deep bench for about 2/3 of the width (about 17') and leave the rest open for my chest....

A 2016 GMC Sierra crew cab is listed as 239" long - approx 20'.

Your 28' deep garage will lose approx 6" on either end for wall and garage door thicknesses. This leaves 27' of floor length.

Of your 7' available, another 6" to a foot is lost to wiggle room for your rear bumper.

You'll have approx 6' or 6'6" total in front of your truck (ask me how I know) and that is tighter than in your artist renderings.

I wish I had a little longer stall - too late now.