What's the simplest travel route from Brisbane to the Moto Park?
for you Mike,
head to Peak Crossing as if your on your way to Harrisville.
don't turn off to Harrisville at Peak Crossing,
instead, go straight ahead for about 20 minutes or so,
you'll enter the locality of Coulson which is sign posted,
and there you'll turn left toward Beaudesert,
the road will cross small bridge with concrete roadway and Qld Moto Park is only about 2klm from that last turn and is sign posted.
basically,
add another leisurely 25minutes from Harrisvile time.