The stamps were mounted in a savings book and cancelled, with each savings book accounting for 250 RM paid. In theory, once the buyer had paid the requisite price and their registration number was reached, they would receive the car. Unfortunately for the buyers, with the start of WWII, the factory was converted to war production in 1939, and those few buyers who had taken delivery of a car had their cars confiscated in exchange for a voucher promising replacement after the war.
After the war, thousands of citizens who had paid money toward a car sued for reimbursement, but they were unsuccessful.
This particular booklet shows that the buyer had paid 1,000 RM (booklets 1-4 @ 250 RM each) of a total purchase price of 1,190 RM.