For the record, the lens I use for all this stuff does not have IS, would be really handy for these shots if it did...
On overcast days it’s easy to get them down that low as there isn’t too much light to begin with, on sunny days a polarizer does the job, I like using one a lot of the time as it removes reflections on the windows and lets you see the driver and inside the car. Lowest ISO possible as well, for me its ISO 50
As far as angles, yes, I pan on those angles when I want to, I almost never rotate shots in software.
When dealing with over 1000 shots from a race meet its best to get as much done in camera then to slowly deal with it later in software...