I am insured through Shannons, I'm 24 with a very clean record. I've been insured with them since 22.
Agreed value on both cars, premium is a little more expensive than Just Cars but I have the total loss salvage option on my Pulsar so in the event it's written off I keep the car for free (minus excess if I'm at fault.) They cover absolutely everything on both of my cars.
It was a little difficult to get insurance with them at first (no garage), but perseverance paid off. They actually scouted me when I had my Pulsar at Autosalon in 2006, then rung me, and the guy who initially signed me up was extremely familiar with my car. I didn't really have to prove I was a car enthusiast, they knew my car.
Neither of my cars are considered high theft risks, interestingly enough.
Premium on the Pulsar is $1100 (limited use cover - max. 2 days per week)
Premium on the Skyline is $1200 (daily use cover)
I'm also in the highest category of risk suburb, so it's quite reasonable.