Every state is different. Follow the rules to the letter. Send the notice of defect to the address in the manual. Wait for them schedule to attempt the last repair. If it seems ok, ask for extended warranties, coverage for payments for lost time in shop etc. This is the last shot before you legally stop dealing and start demanding.
Keep copies of everything.
You don't need to retain a lawyer. Just pay for consults and document reviews.
Once you decide to lemon, park the car and get a rental of a similar vehicle. You can attempt to deal with a Service Manager to work a deal and do a buyback internally, but don't let them make it into a trade, or pull ahead or whatever. The two was it goes is you swap for a new vehicle with the same or higher MSRP, with the mileage charge, or no cost to you if you negotiate it or the it is a full unwind of the deal, you never bought the car. you get everything back. taxes, warranties plus expenses, legal consults, rentals. you pay a fee for usage it's piddly. make sure you deduct all your mileage to and from every service visit.
If you do arbitration go to every single one. Don't let them cancel or offer a settlement. Show up, cost them several hundred and hour and play on your phone. It's non binding. Do not take any offers without a lawyer looking it over and you being 100% satisfied. Don't be afraid to wait, it will take months, you will get paid. they will drag it out. it will cost them. Only when you are before the state arbitration board does it count and by then you will definitely get a settlement that matches state law. make sure it includes all your expenses, has deadlines and penalties. If you are unsure, reject it and go to state arbitration and get the court order so you can slap them with contempt.
Once you are done with the state, if you want to can now file federally with the Magnuson Moss Warranty Act as they broke both laws ( state and federal are seperate and it's not double jeopardy ) and now you have proof with the state ordered buyback. There you can get trebled damages and here you will need a lawyer and very good itemization of how much tome and expense this has cost you.