Sunny day at the races

I used an A6500 and 70-350G to photograph an auto race.  First time being to a large auto race, I had a rough start.  It felt similar to an airshow, with similar issues with needing a longer lens and coping with fast moving objects.  However, it took me a while to work though my settings to figure out what was optimal.

Here are some photos first, in case you want to skip my ramblings.

Somewhat cropped, with some heat distortion

One of the few I didn't need to crop

Very slight crop

Detailed discussion follows of what I learned.

Pretty quickly, I realized I was in AF-S mode for some reason.  (I've been trying to use AF-C.)  Mental note -- check settings before heading out to the event, or at least as soon as you get started.

I wasn't sure what shutter speed would be optimal.  My strategy with moving things like this is to pan with the action.  I love to get some motion blur of the background, but I'm not going to be real steady about it, so I rely on the stabilization to help me out.  I'd say most of the photos have too much motion blur to be really useful at full resolution, but I might be able to rescue some with software or just cut them down to web-size, which will mask any minor blurring.  1/1000 and faster did a better job of freezing the action, but at the cost of the motion blur I was looking for.  1/500 resulted in good motion blur, but often some blurry details on the cars too.   I tried various ones, and I haven't figured out yet what was optimal, but maybe between those two amounts, if you can live with having to pick through the ones that still have too much motion blur.  1/1600 did a pretty good job eliminating the worst motion blur, but also eliminated my panning blur; I still had some issues with minor blurring.  It's going to be hard to get things perfect with so much motion, but I think you just have to decide if panning motion blur is something you're willing to risk having fewer keepers over.  Otherwise, favor faster shutter speeds.
I noticed some shots were focusing on the foreground.  Ugh!  I had "Wide" focus area selected; switched to center-with-lock-on-focus.  OK!  That helped a LOT.  I don't know why I don't use this setting more! 
And M mode with Auto ISO is great.  I locked it to f8.  Even so, there was a bit of "purple fringe" on areas of white, which the software cleaned up entirely.
I really need to make a note of all these settings I used and stick it in my camera bag.  :-/  "Hey dummy, before you get started, check these settings."

But my worst problem was a setting that I had been playing with recently, after a recent thread on the topic.  Silent Shutter.  This probably deserves a separate thread.
Of course, there were some photographers and hobbyists out, mostly with Canon cameras and big lenses.  One guy had a Sigma (Bigma?) xx-600mm lens, while most of the others had grey Canon lenses.  Honestly, I didn't have camera envy.  It turns out that 350mm was more than necessary (on APS-C).  I had to start backing-off on the zoom and frame more loosely, as it was just too hard for me to pan and not get part of the car chopped off.  So, a lot of my best results are 12mp photos instead of 24mp!  Oh well.  I guess as long as you had FF with more than 24mp, you have more room to crop, but I am not sure what I'd do with FF.  My problems were more self-inflicted than camera issues, once I figured out the settings, and even cropping, I would be able to print quite large.  And I didn't mind carrying the camera around for hours.
Sorry for the length, but hopefully someone finds this interesting  and/or helpful.