After you pay for the install you take the recept to centrelink or medi care fill out a form and they post you the $2000 cheque.
Costs seem to range from about $2600 for a carbi car through to $3600 for the latest vapour injection system for late model cars.
It all depends on your set up.
I booked mine in yesterday (navara v6) and will be waiting 8-10 weeks and the installer said his phone is running off the hook with people making bookings.
The only problem i've got is the rebate only covers private use cars and im a tradie and use mine for work i just got to see if there is a way around that.
Also parts may be a problem because there running out off certian tanks and install kits.
here is a link to a RACQ report on LPG
http://www.racq.com.au/cps/rde/xchg/...g_ENA_HTML.htm