Hi OP, I remember your previous threads, what absolute twats. I would be seething. I agree with other posters who have suggested CCTV or taking pictures as evidence.
I understand that you and your DH want to keep the peace but these people will keep getting away with it if someone doesn't do something! I'd be getting as many of your neighbour's as possible on side to make their lives a misery.
If you have 5mo twins you must be up at the crack of dawn and during the night. I would make a point of getting your DH to casually pop round at all hours (literally 3am, 4am etc) and insist they move as you need to get out urgently. If they decline, you've still succeeded at disturbing their sleep. Do this most nights. Tell them you won't be held responsible for any damage done to their car if you have to shift it out of the way.
I would also get friends or family to block them in when they park like cunts.
If you have a car you don't care much about, you could try blocking their driveway or parking across the front of their house.
Honestly, I would also be bad mouthing his precious business to anyone who would listen. Get friends and family to write shite reviews and spread the word that he's a knutjob.