After I sign my title over to a new buyer but don't take the plates off right away will I still be liable for the vehicle

Do you have a copy of the bill of sale signed by you and by them to prove in court, you sold it to a specific person?

How long will they take to register it ?

I sold a car once, three years latter it was found involved in a hit and run, deserted. The person who I sold it to, never registed it, guess where the police came?

You will be OK if you got all the paper work done, but I always pull my plates, but the car will still show up owned by you, till they take the title in and register it.

Most states REQUIRE that you remove the plates. I would check with the office where you get your plates from. It is also a good idea to do a bill of sale, even if your state dosen't require it. Make sure you have the VIN, good details of the transaction, including stating that you are removing the plates, ant the buyer is resopnsible to get new ones. Some states also require the seller to get an emissions certificate for the car. Be sure to get both signatures. A buyer with good intentions will have no problem with this.