It's a balancing act between the idea that it's always the job of the passing car to complete the pass safely, and the idea that you should let obviously faster cars by.
The absolute best advice you can get is just be predictable. That means do not change what you're doing corner to corner. But the worst thing you can do is defiantly drive the racing line with no regard for who's around you. I know the rules say the overtaking car has the responsibility to pass safely, but Lemons has too many cars on track for running the ideal racing line constantly. Leave a lane for cars to get around you no matter where you are and everyone will be happy. Check your mirrors coming into corners too, happens all the time that someone tries to stick a nose in where you aren't expecting.
I'm not saying you have to immediately let by any car that is the slightest bit faster than you, you can make someone work for a pass. But please please don't be that guy that just drives the racing line the whole time chopping off the noses of cars that have lapped you several times that hour. I've come across enough cars that will drive right to the edge of the track on corner exit even when you're up next to them and actively passing them, forcing either a forceful amount of brakes, or going off track to avoid contact. That isn't the way to make friends in Lemons.
I started in a C class car, so I learned to race by living in my mirrors. Now I have a much faster car, but I still leave a lane anytime I'm running near someone that's faster or near my speed. It's just polite. If I find a car I'm evenly matched with I will defend my position, but I will always make sure there is a path for them to go around in the event that I slip up or they just find a faster way though a corner. I'm probably on the more polite end of the driving spectrum in that regard.
Point bys for blatantly faster cars is a nice gesture, but not required. I'll point by cars I know are in the top 10 just so they know where I would like them to pass me. Makes it safer for both of us and they can go by me knowing I'm not going to shut the door on them, and I know where they'll be. Plus usually if I let them by I can try to chase them for a lap and learn their traffic lines.
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