IIRC you'd have a tough time even insuring a car that is >5 years old.
Risk is also assessed on an individual level, not necessarily on the thing being bought. While it might factor into it, I'm pretty sure that it doesn't go down to the new vs. 2nd hand level. Even if that was the case then it would make more sense that 2nd hand purchases carry a higher risk since there is no way to gauge the way the previous owner maintained it.
It's all about the VALUE of the product being insured not whether it's new or second hand.
A new car is instantly second hand anyway.
And you are confusing the 5 year thing with getting finance from the bank.
I have a 12 year old Opel Corsa which cost something like R180 a month because it's old and worse like 25k.
I also have a 5 year old Golf GTI which costs R450 odd a month because it's worth 200k.
Same risk profile as I'm one and the same person.
If I replace either car logic dictates the new one will be more expensive. Depending what it is it will have a certain repair cost associated with it. Therefore it's guaranteed to cost more money to insure.
It's really not that hard to figure out what he meant.
Also how the previous owner treated it is irrelevant to insurance. You are insuring against mechanical faults (well that's a difference insurance) you are insuring against someone crashing into you.
Which is why more exotic cars cost more to insure even of their base value is the same as other cars, because the replacement parts cost that much more.