Yeah I wouldn’t use the 100LL (AvGas) in a car even if it doesn’t have converters or oxygen sensors. The “low lead” is in comparison to other aviation gasolines, and still has a much higher content of lead in it compared to even leaded gasolines.
I use the Delta Sonic 100 octane stuff in my car all the time and I’ve never had a problem with it, and my car is very picky. If I try to run the 100 octane map with 98 or 99 it will have a small amount of detonation.