There are many factors involved here.
Yes cars are designed to "crumble" to reduce the impace to the passenger.
The beetle actually has a bumper.
The angle the intregra was hit could play a large roll in the damaged too. Hitting head on the beetle may have had an advantage.
There are a lot of factors involved in an accident. Safety ratings don't always paint a true picture either.
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1995 Mustang GT