Regarding comments that you should bend over and take it: bullcrap.
This is the second most expensive investment that you'll ever make,
and through their negligence you've been damaged. Why don't they just
come over to your house and throw rocks through your windows?

They should be well aware of these problems, and should have contacted
your employer to arrange for the employees to park somewhere else.
Even if it required renting a parking lot and providing a free
shuttle.

Touch base with your fellow employees and seek the support of your
employer too. You aren't going to impress steelworkers by approaching
this individually like a gentleman. If they cared, they'd have done
something to prevent it.

You can pursue in small claim court, no lawyer is allowed to represent
either party in California by the way. So it will be two amateurs
duking it out, although a 'businessman' probably has had more exposure
to 'the system' and may have an advantage. Frankly, unless the car is
extensively damaged, or you can get a number of coworkers to join in,
this doesn't really sound like something worth a good lawyer.

Unless your car is almost new, the rust spots were not caused by
shipping. (They're shipped on the railroad and can pick up steel dust
from the tracks.)

Best of luck. JM