The car manufacturer is one of the first tranche of brands to sign up to Facebook Deals, the social-networking site's mobile scheme that rewards users for 'checking in' at retail partners.
Starbucks, Yo! Sushi and Benetton are among other partners for the scheme, which launched in London on Monday, but Mazda is the only one experimenting with transactions of more than £1000.
It aims to use Facebook Deals to sell 100 of its MX-5 model before 7 March, in what is being viewed as a test case for the sale of high-value items.
Consumers can obtain a 20% discount by checking in at one of five participating UK dealers. Mazda intends to drive footfall by entering participating Facebook users into a competition to win the use of a Mazda MX-5 Miyako Special Edition for five months.
Claire Andrews, marketing director at Mazda UK, said: 'We want to have a time frame to assess the success and then decide whether to take it further.'
The trial coincides with the launch of the brand's 'Experience Mazda' Facebook page. Andrews said gaining fans on the page would be another key measure of the success of the Facebook partnership.