If guns were as regulated as cars, a concealed carry license from Kansas would be valid in New York City and Washington DC.
If guns were as regulated as cars, 16 year old teenagers would be able to lawfully carry guns.
If guns were as regulated as cars, people could buy guns without going through a NICS check first.
If guns were as regulated as cars, you could install a muffler on a gun without paying a surtax or going through a background check.