If there’s a car you want at a price you think is fair in q4 go right ahead and buy it. As it may disappear. If there’s nothing that interests you wait it out until Q1. Though Brexit may crop back up by then.
Current Car
KIA Sportage GT Line Mhev
Previous Cars
Peugeot 5008 Allure Premium
VW Touran SEL
Citreon C4 Picasso