Tim-
The way I read that it pertains to a "REPAIR SHOP". I see you where asked about this previously, but haven't seen you're response. Is it a "REPAIR SHOP"? If not what kind of shop is it?
What sources are you using for information on the laws that pertain to this state and situation?
Look man... you got suckered in by some D-Bag who was all smiles, saying nice things, laughing with you in his office, which is probably covered with pictures of rainbows, kittens and unicorns. Yeah, you're at fault for not doing your home work before hand and covering all the bases with signed agreements. It's a messed up world in a lot of ways these days. Sadly we have to protect ourselves in ways that we haven't had to use as much in the past. Ways that seem silly and are kind of foreign to us.
Right now you really need to be focused on "RECOVERY". You trusted this guy to honor his word. He claims to have no memory of that conversation or agreement. TIM!!! Wake up...that's your sign!!! He's done this before and knows the different avenues people will take and what will happen. Right now HE HAS YOUR CAR!!! That empowers him and weakens you. You want your car back and he knows it. He's basically holding it hostage. Thinking he isn't already two steps ahead of you is a mistake. This sounds like the kind of guy who suddenly wants to charge you months of storage fee's in addition to the inflated, because you suddenly don't agree.
Tim...the number one thing I would be looking at is how to recover your car ASAP. You say that there is nothing in writing. If that's true, then you need to be looking into the laws that cover you picking up your car without paying for the work. You can always haggle that out later. TAKE AWAY THE HOLD HE HAS OVER YOU!!!!! How well do you think he is going to take care of your car while you two battle it out in court? Will you then have to have a second legal battle over damages done to the car while it sat in his shop? I'm not saying pay the man right now. NO!

I'm saying get your car if you can and then argue the bill. If you hold all the cards...things will change. Suddenly he remember the "deal", apologizes for the trouble while hold up a picture of cute puppy or something, all in the hopes you will pay him the amount you two originally agreed on.
I don't mean to be a jerk to you Tim. I just really hate this kind of crap. It pains me to see this kind of crap over and over. I've had a year of losses and learned just how down right filthy people you think are good, honorable and trust worthy can be. People you where close to. Protect your self, your family and your money.