This is not necessarily true. Operation of a motor vehicle on private property is regulated to some degree. First off, you can’t just defeat the carburation system, or change the bore.
“...you can’t just defeat the carburation system, or change the bore.”
That would constrain the kind of car that could be driven, while leaving intact any right to drive an unconstrained car provided “You can drive all you want on your private land without a license” thus leaving as false the statement “Driving a car is a PRIVILEGE, not a RIGHT“.
Defeat the carburetion system? The purpose of a carburetor is to make an air/fuel emulsion at stoichiometric ratio. If you defeat the carburetion system, your car will be inoperable. Seems like a waste of time to make that illegal. Besides, new cars don't even use carburetors anymore.
I'm also fairly certain it is not illegal to change the cylinder bore. In fact, it is standard procedure when refurbishing an engine to original specs. For example, if piston to cylinder clearance of a typical small block V8 reaches .008", the block must be bored and oversized pistons installed to insure proper compression and reduce oil consumption. Typically .030" oversized is used.