Whoa whoa whoa. Every one take a deep breath here, lol. OP's head must be swirling with all this advice. (driveway threads are the best).
I concur with the correct assessments of improper grading (no ditches, no crown, etc) and type of stone used so far (large, round, no fines). It will obviously keep leading to this problem.
However, I also don't see any obvious erosion in the pics, or muddy spots. Might be a pretty deep layer of this large rock. You have a good start here.
But the OP has an MX5800! Just get a nice HEAVY land plane, and start pulling that driveway back and forth. You'll get it smoothed out in no time. If it were me and money wasn't a problem, I would definitely get that nice base rock covered up with 3 to 4 more inches of finer gravel. If you have sandy soil and dont want to buy any new gravel, you could even mix in a light amount of sand with those large driveway stones, and keep working it with the land plane. Drive up and down a bunch of times to pre-compact it before you get your next UPS guy doing 20 mph on it, lol.
Lots of folks advocating for crusher run, with fines. Certainly a solid way to go, but just realize that the fines that help lock the rock together also trap water, so you get pot holes and puddles eventually. If you want to keep that low sports car clean, maybe not the best way to go. My 1000' driveway is 3/4"-minus CLEAN, no fines, over a well compacted base of larger rock. Yes, it moves around a bit and starts to washboard when people drive too fast, but 10 minutes on my tractor with the rear blade or box blade has it perfectly smooth again - maybe 2 or 3 times a year. I also want a land plane eventually though.