You will probably get a strange look down here trying to turn in an old plate, you will be asked, oh you want me to throw it away for you? (no receipt) and into the trash it goes…

TN does not require you to turn in your plates,

Nor does NJ. While it’s a good idea to turn-in your old plates (and get a receipt for them), it’s not required.
The motor vehicle law in Tennessee changed in 2024 and it states:
"If a registrant has not surrendered his certificate of registration and registration plates or obtained motor vehicle liability insurance within 90 days from the date of cancellation of motor vehicle liability insurance, the director shall suspend the driver’s license of any such registrant."
As for New Jersey, they do not require you to surrender your plates if you cancel your insurance but intend to keep the car, but you must cancel the registration. However, you must surrender your plates if you are selling the car, junking it, or otherwise taking it out of service permanently.
So, the best advice then is to call your local Department of Motor Vehicles and get the rules and laws as it applies to your location…
Well in late 2024 I sold a vehicle (took title only to dmv) and went down to the dmv to do it and they never asked for the old plate or registration and I still have both, and all I did was email the ins agent and said cancel the ins on said car, he did no issues…
Also in March of this year, my son totaled out his Civic (single car and no property damage), while in the hospital emailed the ins company and said to cancel the vehicle(didn’t even have the police report yet), never said why and it was never asked, just renewed and vehicle is off and no issues, also I kept the old plate…The tow lot just sent a letter saying it would be sold at action, I’d already talked to them and cleaned out the car the day after the wreck and we talked about how it would all go down…
But yes, if you have plates on a vehicle and it’s driven, you do have to have ins now, they have started cracking down on that… But had a guy that bought non drivable 93 Mustang and put plates on it (codes) and never added ins to it, no issues, just sold it couple weeks ago…
If your car uses a RFID chip in the key, the ECM could lose the keys registration and you will need a licensed locksmith to reprogram the ECM. Your dealer can do this also but you would probably have to tow the car to him for this service. It would be best to hook up a battery maintainer to the battery and leave it in the vehicle.

If your car uses a RFID chip in the key, the ECM could lose the keys registration and you will need a licensed locksmith to reprogram the ECM. Your dealer can do this also but you would probably have to tow the car to him for this service. It would be best to hook up a battery maintainer to the battery and leave it in the vehicle.
Hi Keith:
Can you help me understand this?
Doesn’t the ECM use persistent memory to store this kind of data?
Thank you.
I haven’t seen why the OP can’t use a battery tender.
Doesn’t Clueless live in an apartment, therefore can’t plug in a battery tender?
Solar powered one??
That’s a good idea, solar powered batter tender, inside the car in a sunny location.
Unless he is going to park it in a parking garage…
I would prefer disconnecting the battery, Lexus IS vehicles have been a target for thieves.
Well yes, but it is not that persistent. Well at least not on Nissans. They lose the code if the battery is out for more than three months, at least with the first and second gen systems. I would imagine that eventually they would use the technology from thumb drives that would last longer.

Nissans. They lose the code if the battery is out for more than three months, at least with the first and second gen systems.
25 years ago? Then it is not a concern. What is the failure rate? 1 out of 10,000?
In the late 1990’s I had one or two Chryslers with immobilizers that lost the key registration for both keys, I replaced the immobilizer modules. A vehicle shouldn’t be returned to a customer with an unreliable immobilizer system.
The OP has a Lexus, the most common problem that I have seen on Smart Key systems is when locksmiths try to register a new key and cause the system lock up, then the certification module needs to be replaced.

I would imagine that eventually they would use the technology from thumb drives that would last longer.
EEPROM and Flash memory have been around for a l-o-n-g time already and EEPROM is commonly used as separate as well as microcontroller integrated memory for non-volatile storage of variable data. Flash is more commonly used for program memory (and thumb drives) since it is block erasable versus single cell for EEPROM.
If you look up the persistence specs for EEPROM, it is typically greater than 200 years.
I took apart an ECM maybe 20 years ago and it had a serial EEPROM hanging off the microcontroller.
No doubt, various configurations exist(ed) and some manufacturers may have chosen some type of ultra-low power RAM based storage that can survive months off the bulk capacitance but I suspect they are in the minority and old technology. EEPROM, in the last couple decades at least, has become ubiquitous and just about every controller in the car has some to store data related to the system it controls.
Maybe, maybe not. Do you know for sure what type of memory module is in the OPs Lexus? I don’t. I threw that out there as a possibility and suggested that he leave the battery in and hooked up to a maintainer.
But if you know for sure that he wont lose the key programming, then by all means, ignore my comment.
No offense to Tennessee law but I don’t see how it makes sense to tie a particular vehicle to a particular drivers license? Makes no sense. Multiple cars, one driver or multiple drivers, one disabled car.
At any rate I would never store a car without maintaining at least liability coverage, and just as easy and preferred to keep the registration up. If not just sell the thing and buy another when th3 time comes.
Now a few years ago I read somewhere that when new cars are delivered to dealers, there is a fuse not installed or a switch, or something to allow them to sit on the lot for months without a problem. Don’t know if that just shuts all the electronics off or what. Cars otherwise don’t like to sit unused.

No offense to Tennessee law but I don’t see how it makes sense to tie a particular vehicle to a particular drivers license? Makes no sense. Multiple cars, one driver or multiple drivers, one disabled car.
Huhh??? …
See post 22. Change in Tennessee law. But I do believe this place is doing some mixing and matching.
Wow, that was 17 days ago lol… OK I gotcha, I pretty much know how it all works, I am just not smart enough to explain it…