I don't know of any internet PDLs that take car titles, so I will assume you actually went into an office to sign for the loan. ... Which means they are most likely licensed in your state.
Now we all know that title loans are just a payday loan with your car title attached. But at least in my state (IL), all the new PDL laws don't apply to title loans. So basically if you sign the contract, you're screwed.
These places charge daily (simple) interest. If you keep the loan open for a year and six months, then they are going to charge you for a year and six months worth of interest. And most states do allow a late fee for each payment more than 10 days late.
You can check with your state to see if they are license; and you can look up your laws on how they can charge interest and fees. Your state DFI probably has a website which shows what lenders can/can't do.
If they are legit, then your best bet is to payoff the loan as quick as possible. Pay them anything extra you can, so that you can get your principal paid down. The lower your principal is, the less interest they will charge.