This is wonderful. I wish they did the same about modifications done to increase the noise. I've got 2 people living nearby that both have straight-piped their car and I literally cover my ears when they pass by. My Watch literally tells me that a noise peak happened when they drive by.
1) Look up your city ordinances on sound, there should be copies of this is the reference section of your city's public library. Identify the ordinance and paragraph that the people nearby are violating. Record/video one or more violations on your phone.
2) Call the police, don't "complain about the noise", tell them you want to "swear out a complaint" for violating ordinance x, paragraph y. They are obligated to take your complaint and forward it to the District Attorney[1].
3) You will probably be called as a witness if the folks with the noisy cars choose a trial.
[1] When a police officer hears a complaint, they can "investigate", and then "cite" the offender. It is up to the officer's discretion. That citation is the sworn complaint from the officer of the offending behavior. When the police refuse to do their job, everyone has the right to "step in" to that role and swear out a complaint. The downside is that retaliating against an officer is 'scary' but retaliating against a neighbor isn't. This can result in a variety of negative externalities that may be criminal but hard to prove (car getting 'keyed', tires slashed, rocks thrown through windows, feces on your porch, Etc.)
Because taking on the job of enforcement when the cops let you down incurs significant personal risk, I usually suggest people make an appointment with their representative on the city's governing body, city manager, or district attorney and encourage them to actually do their job. Editorials in the local paper are good to, but projecting soft power as a voter in that way is less likely to blow back directly on you. I can also take longer and be less successful but sending emails to the DA with repeat infractions over and over can often convince them of the need for enforcement.