Won't stop chasing cars!!

Training classes didn't work cuz YOU didn't get it.  Now before you think I'm being rude, let me explain.  Classes are to teach YOU to teach your dog.  The trainer doesn't train the dog, she trains the owners so that they have the tools that they need to work with their dog.
 
When walking this boy, I'd opt for places AWAY from the street to start.  Even if that means that you have to put him int he car and DRIVE him someplace to walk him.  And I would become the most fascinating thing in the universe when I have him on leash.  When I walk my dogs onleash, I talk to them constantly.  Their attention is really focused on ME.  See now it's Mom and JUST me are out for a walk...everything that Mom says, she's saying to ME and I don't wanna miss something good that Mom might say....like what a good girl I am, how nice I walk, or come here and get a liver treat!!  I don't wanna miss anything!!  This is MY time with Mom and I don't have to share her with ANYONE else.[]
 
I'd immediately switch to a harness to keep this boy from hurting himself further, and an Easy Walk harness would be a better option to correct the pulling.  The bottom line here is that your dog is NOT leash trained, and you need to go back to the basics, step one, and start again.
 
I'd also really suggest that you try classes again.

I agree, and I would add that if you went to a traditional class where the dogs all just got yanked around in a circle trying to "heel", you could have done better, especially with a Pug (they love to pull).
Why not try clicker training?  You can find a class at [linkhttp://www.clickertraining.com]www.clickertraining.com[/link]. You will need to start slowly, and not let him practice bad behavior, so Glenda's suggestion of putting him in an Easy Walk Harness ([linkhttp://www.premierpet.com]www.premierpet.com[/link]) is a good one.  He will walk nicely on that until you get him trained.  Training takes longer than a six week class - it's really a lifetime endeavor.  There are no shortcuts!