Insurance depends on a number of factors in NSW like the NRMA:-
Red P's, Green P's, age of driver, number of policies you hold with the insurer, number of claims you have had, how many years with the same insurer, has any insurer ever refused claims in the last 5 years, garaged over night, how many K's you drive in a year, age of vehicle, no finance, licence suspended/cancelled in last 2 years, bald tyres, leaving car unlocked, V8 or V6, modifications etc, alcohol or drug related issues, criminal history, age excess and the list goes on and on.
Just remember that all your history is now related on a computer some where and may be accessed by the authorised insurer.
It is like having an Australian Card but it is all stored in cyber space.
Car repairers do not want to know you if you are insured with Coles, Wollies, Meercat and the ones that operate out of the boot of a FC Holden....so stay with respected insurers.