Officers set up the program on Gore Road near Cambridge on the night of Aug. 12.
Police say that around 10 p.m., officers found a quantity of crystal meth in a black pickup truck and then found more crystal meth in a grey car an hour later.
A 29-year-old woman from Cambridge and a 28-year-old woman from Kitchener were arrested in the two incidents.
Both drivers were also charged with driving without insurance. The woman driving the pickup truck was also charged with theft under $5,000 and two counts of possession of stolen property as police allege the licence plates were stolen.
They will both make court appearances in Guelph later this month.