Given that this is a daily, and you use it for occasional motorsport what I would be genuinely concerned about is the 'fuckwit factor'.
It would take one fuckwit (of the thousands on Perth roads) to smash into your car, or indeed one mistake on a track day, to write the whole car off. I'm guessing the insurance value is somewhere around $10K.
Fair enough spend $8K on a decent donk, but if you lost that in a single head on smash, what then? Part of the reason a later model build is a better idea for a build is because if you crashed it, at least you'd get $25k-30k back in which to take stock, and buy something else.
The alternative is to insure your car for way more than it's worth of course..
Not having a go, it's not my money, but just make sure you've thought about that.
