Ideally, you should have had an attorney sooner. Retain one immediately. Use the Avvo search tool and/or your county bar association to find one.

"Now the seller is demanding full payment without providing registration documents & threatening to repo the car. " It seems the seller has...

This is a landlord/tenant issue - moving accordingly. There being no executed lease, it appears you are renting month-to-month.

The terms of the executed contract control. You SHOULD have been given a copy of it when you left the dealership. Have it reviewed by counsel...

Moving to landlord/tenant, which is more relevant. Contact your county bar association regarding low/pro bono programs.

Moving to landlord/tenant. "He's violated several landlord tenant laws and has used coercion and other tactics." Then retain counsel and sue...

This has nothing to do with animal law, where Avvo seems - again - to have dumped your question. Moving to family, which seems more relevant. If...

Read your ticket, which has all the claims information on it. YOU missed the call, by your own admission. I doubt you have a case.

A call to the AG seems a very cost-effective place to start. Be sure to have all your documents in front of you when you call.

I assume by "rims" you really mean wheels. At any rate, it's not your car and not your problem. As neither you nor we know what the contract...