CAR Structural Damage but CLEAN TITLE? Why is the car considered clean with a structural damage? Can the structural damage be minimal?

A car can have structural damage without being designated a total loss by an insurance company, at which point a salvage title would apply.

The title is about ownership of the vehicle, not the condition of the vehicle. 

Insurance companies caused confusion with salvage titles, etc.  My state never had any of that.  I think California started it. 

A "clean" or "clear" title in my humble opinion is one that has no "secured party" (bank or lending institution) attached to it, in the form of a LIEN.  It only has an OWNER and nobody else listed.

The only way are car has a salvaged title is when it has been totaled. If the dealer just repaired the car in their body shop the title won't be "salvaged". They should disclose to you that repairs were done.

Car Fax is "NOT CAR FACTS".  Car Fax is a web site with that name and those people who report to that site is how they get their car registered in their system.   For those that do repair work without reporting, are UNKNOWN.(clean).

Usually structural damage means bent FRAME. Most times it is a Piece of junk now. It depends on the shops. The car has to be looked at by a frame shop and a wheel alignment shop to see if the car is repairable. Some are.

Later or 5 years I find out the car was "Front ended", "Rear ended" and Rolled and yet for the original owner it was worth fixing it up and reselling it(maybe he was an autobody man or a frame man.

. The fact is when a car gets structural damage, it can be repaired but then must be inspected by the same kind of inspectors the inspect new cars from Department of Transport (aka DoT) to be sure it is suitable for the road.  If it passes those inspections then it is clean as any problem has been fixed.  No different than a new car.

The title remains clean as long as the vehicle is repairable.

If a car changes hands in a private party transaction with buyer and seller agreeing to "as is" condition, the title will not reflect any damage.

A buddy bought a 57' Ford Panel that had one side totally ripped one end to the other and he did a beautiful job splicing one side he purchased from a wrecking yard, and his title did not change.

May have been fixed without filing an insurance claim.

Titles are clean because the person has it in hand (no liens or encumbrances ) - when cars are damaged the titles don't change - you only get a salvage title (not clean per se) when  a car is totaled by the insurance company and is then repaired and put back into service with a salvage title. 

Answered already here -  /question/index?qid=20201...

SOME states don't have a 'salvage title' ......................