There's been a lot of pent-up demand over lockdown. People haven't been able to buy cars during this period and car auctions haven't been running (so dealers have been struggling to source stock). Now restrictions are being lifted, good used cars are flying out of showrooms and dealers aren't having to put much effort in. This is starting to change, though, as more used cars are trickling through and demand is dropping. This will continue after the September registration change as more used cars hit the market (as part-exchange vehicles) and demand drops. So yes, I suspect you'll find it easier to get a good deal in September/October.