Also be very very wary of E4's in Australia.
Most are rebirths... as in an Australian Lancer shell has been used, and the E4 gear has been transferred in to.
First check will be what is the car actually registered as. For an E4, even in WA you really want it to be a yellow plate import.
Second obvious check would be that a CN9A number is stamped on the firewall. Even if it is crossed out it is at least a good sign that it was a genuine Evo 4 at some stage.
Third check and once again a registration or REVS check will show, see what colour the car was/is registered as and just see the vehicles history
Basically there are a number of ways that these vehicles can be re-birthed.
1) Bring in Evo, cut out firewall or section of firewall and weld on a standard lancer chassis number then register it as a Lancer <<< you do not want this one
2) Bring in Evo, acquire aus delivered standard lancer, transfer all evo components in to lancer the lancer chassis <<< this kind of car can be registered in WA depending on what process was followed at the time
3) Genuine Evo with a 6REP/6REV respamped chassis number <<< this is your best out of this bunch