The trip across the Nullarbor from Adelaide to Perth is one of the longer road trips in Australia.  Endless straight roads that seem to go forever....Stopovers at some magic places like the Flinders Ranges, and across at Streaky Bay , make the journey worthwhile before hitting the South West Coast of WA.  From there you hit the coast and head up to Perth via Esperance, Albany & Margaret River.

 

 

Whale watching at Albany starts in May and continues through to October.  Definitely allow 1 or 2 days while heading through this area to ensure you have a great experience. 

 

Adelaide to Perth via Flinders Ranges, Port Lincoln, Esperance and the South West Coast

 

With this map just remove the places that you do not plan to visit (i.e maybe the Flinders Ranges or Port Lincoln depending on your time) and the map will automatically adjust for you.