Well last year, when those photos were taken, we all just stood on on folding chairs.
This year we lucked out and for just the cost of materials a member of our club had an 18 foot 6 foot high driver stand built from treated lumber. We move it in and out of place with a one meter square dolly. The materials were about 600 US dollars.
I kind of thought mentioning that was out of the realm of DIY tracks.