I’m aware of the ancient paradox of the Ship of Theseus and how it has been estimated that the parts on the USS Constitution are only 10% original, yet it is treated as the same ship.
How does this apply to automobiles, and especially to their legal registration (any jurisdiction is fine)? It seems absurd to say that replacing the front left headlight on a 2008 Ford Focus results in a legally different car, and it would also seem absurd to say that replacing the battery and alternator because they died but keeping everything else would create a new car. Are there any jurisdictions that have hard and fast rules, either in statutory or case law, that define when a car has had so many parts replaced that it is no longer legally the same car and must be registered anew? What if you take a car and replace the transmission, windshield, starter, front differential, shocks, gas tank, radiator, catalytic converter, and right rear door but keep everything else? Is the VIN number tied to the engine, and anything but the engine can be replaced? If you take two 2010 Chevy Malibus and swap the engines, do you have to swap the titles and registration cards too because the legal details are tied to the engine?
A friend of mine owns a custom built race car, it was built in 1960. The firewall and floorpan came from a 1960 Volvo so the car is titled as a 1960 Volvo. None of hte rest of the car is Volvo, it was built with Triumph running gear but about 20 years ago was switched over to Ford power.
But in your example, I don’t know of any car manufacturer that tied the VIN of a vehicle to the engine, it has always been the chassis of the vehicle. I have done many engine swaps over the years and never had to retitle the vehicles.
I recall reading a book about the coal mining operators in West Virginia(?). The law required updated safer equipment in the very old mines, but the existing equipment could be kept grandfathered until it was replaced. The author claimed a significant number of mines replaced the equipment with similar or rebuilt ones instead of the newer, safer models - but transferred the nameplate from the old equipment, thus satisfying the law that the equipment was valid because it was gradfathered.
I would hazard a guess that the VIN on the frame is what uniquely identifies an automobile, if you had to pick one item.
As said above, the VIN for a car or motorcycle is assigned to the frame, unless you’re dealing with a pre-1958 vehicle, in which case, they generally went with an engine block ID number.
If you’re just replacing parts of your car, it’s still the same car, legally speaking, unless you replace the frame. This becomes a big issue with restoring classic cars with frame damage, but it’s a non-issue for a 2008 Focus.
VW stopped importing the old air-cooled beetle into Canada and the US in the late '70s but they were still built in Mexico through the 2004 model year. The Mexican bugs could not be imported because they did not meet safety or emissions standards.
There was, however, a bit of a grey market industry in the US south west “restoring” old VWs with Mexican parts. A customer would supply the restoration business with an old German VW chassis and the restorer would remove the VIN label and attach a new Mexican beetle to it. The car was then “legally” the old VW.
I don’t have a cite but it is my belief that this business model existed before 2004 but I don’t know how successful it was legally or financially.
I’m not sure of my facts, but here is what I believe.
(1) I believe that the vehicle’s “identity” is tied to the chassis. You can do anything but don’t step on my blue suede chassis, and it’s still the “same” car. The VIN is tied to the chassis.
(2) I believe that the reading on the odometer is likewise. You can replace the entire engine, but that doesn’t reset the odometer to zero. The mileage on the odometer is the mileage on the chassis, not the mileage on the engine.
An tangential anecdote I meant to include above, but missed edit window:
The former Mid-State Bank branch in Paso Robles CA had an antique Conestoga wagon on a pedestal in the parking lot. It came to be an iconic symbol for the “pioneer” history of the town. They always hitched it up to horses and pulled it along during the annual big Pioneer Day parade (and probably still do). One un-fine night circa 10-or-so years ago, some jerk thought it would be great fun to torch it. So it got burned to toast, with only a slightly charred chassis remaining.
After some searching and ruminating, they found a genuine Amish cartwright somewhere in Pennsylvania or some such place. The remains of the wagon were shipped there, and the guy re-built the wagon on the same chassis. So it’s an almost-entirely new wagon, built according to vintage Conestoga wagon plans by a genuine Amish cartwright. Everybody seems to accept that it’s still the Paso Robles iconic pioneer Conestoga wagon.
Does the legal concept of a ‘totaled’ car enter into this?
I know that some cars can be damaged enough in an accident or flood to be considered a total loss by insurance, but sometimes people repair them and continue to use them (or sell them). Most states have laws that require a notation of this on the car’s registration papers. But I think it is still the same, original registration.
I ran out of time to post on this before. FWD cars can be totalled from rear end damage, and then cut in half and a whole other back of the car welded on. It’s relatively easy to do with no transmission extending to the back wheels. This spurred some state laws about reporting. I suppose there is a way to do this safely, but some cars have broken in half on the road because of cheap welding jobs. The problem in tracking this that it’s primarily reported by insurance companies, and they won’t even evaluate a car that has no collision insurance if it’s condition is otherwise unrelated to insurance claims. Carfax records also depend on individual shops to report major repairs, and those aren’t always reported either.
The problem is that “chassis” is a bit of an ambiguous term these days. It made a lot of sense back when cars all had big steel frames onto which everything was bolted, but these days most are monocoques where everything is bolted onto the body itself. Virtually any serious modifications to a modern car is going to end up replacing large portions of the chassis.
The actual legitimate way to import a Mexi-Beetle was to take the floorpan off an old 60’s Beetle and then weld it into a new Beetle. The Beetle was particularly ambiguous because it didn’t even have a main rigid unibody-- it was literally just a bunch of parts bolted together. There was an old VW commercial where they built a new car out of parts at a parts department, and you could still conceivably do that out of the aftermarket parts catalogs they have today. The closest thing to a rigid frame the VW’s have was the floorpan and heater channels, so it was decided that that was the “part” that belonged to the vehicle number.
Certainly a few Mexi-Beetles came in without actually changing the floorpan, but what you can get away with varies quite a lot by state. My state will give you a set of plates on anything with wheels, regardless of what those pesky feds say. I imagine this is not the case in a state with regular inspections and such.
This is a kit car based on the Miata that basically chucks the body and keeps everything else. In most states, it can still be registered as an 89-05 Miata.
Of course lots of people also upgrade the engine, transmission, suspension, wheels, etc while they’re at it. I’m sure there’s a few “Miatas” running around that have close to zero actual Mazda parts.