Detectives stopped the car on the Eyre Highway.
A search allegedly revealed 6kg of MDMA (ecstasy) pills, 3.5kg of heroin and 3.8kg of cocaine.
Police said the drugs were valued at between $6.5 million and $7 million.
Serious and Organised Crime detectives charged a 35-year-old Kalgoorlie man with possessing a prohibited drug with intent to sell or supply in relation to the MDMA pills.
He was refused bail and appeared in the Kalgoorlie Magistrates Court yesterday.
He is next due to appear in the same court on Thursday.
Police said further charges were likely in relation to the heroin and cocaine.
Anyone with information regarding the manufacture or distribution of illicit drugs is urged to call Crime Stoppers on 1800 333 000.
Callers can remain anonymous.
Story via Yahoo