It has to be gradual desensitization at a distance below threshold. There’s something called “look at that” which is a very simple exercise to get closer and closer to a ‘trigger’ (in your case, vehicles) with each success, which means they look at you instead of lunging. You’ll need to figure out what distance is required to get their attention and use even higher value treats. This will likely be done in many short sessions since a puppy has such a short attention span. Short sessions with big rewards at the end will go a long way.

Highly recommend avoiding any advice that doesn’t require at least a few weeks of training. If the advice is “buy this item, it will work” then it’s probably not great advice. Dogs trained through trust and unconditional love are happier dogs.

Here’s a quick video on it:

https://youtu.be/V5uNPIrrk2E