Is not all about the machine... You have to know all the process, from alignment, heights, machine adjust, room adjust, materials, linearization, profiling (and profiling to archive x), rip, best way to prepare files for that rip... S40600 is not the best machine, but in well use, you wont find much difference with better machines.
I assume you are looking to print high quality photos on paper too? Then dont look for outdoor printers. Look for a water based machine with less drop width (pl). But again, if you dont know to calibrate it, no machine will be perfect for perfect results.
Btw... If you want to print labels too, buy a label printer. But for car wraps... Look at the cheap sr1641 pro with ms51 inks. We have one from a year ago and works really good (and Its a dream to adjust it all)
With any 1440ppp machine if you cant read a 6pt text, adjust the machine (or because of my age, my eye lenses lol)