Just under 1k for everything but I got 2x setups (enclosure, motherboard, psu, drive adatper) from the US to save on shipping.
Might be a little more now that our dollar sucks ass but general run down:
VoomPC-2 Barebones kit - US$230 + shipping
1Gb DDR2 RAM - AU$25
160Gb (yes my bad, it's actually 160Gb) 2.5" HDD - AU$65
Slim DVD drive/burner - AU$69
7" manual single din in dash touchscreen - AU$569 (seems to have gone up by $100 since I got mine)
So yeah, the screen was pretty much half the cost but I wanted something quality with VGA input, in-dash and non-motorised If you're not so picky on screens there are alternatives, i.e. if you wanted to mould into the dash I'd go for a 10.4" Samsung panel
Edit: the big winner the is M2-ATX power supply that comes with the kit, it's rather intelligent and has a lockout feature so it won't just cut power to the pc when you turn the ignition off, it keeps running for a certain amount of time (that you can set) and shuts down the pc properly. It also handles the voltage drop when cranking so the pc won't reset!