I used to be able to order in Q1 for april handover and every single car i was looking at getting went up in ap from Q4 (when i could not order the car) So I would say order it at the 1st available opportunity as then hopefully it will be available for handover on the 4th of march. As other have said if you set on one car then, talk to the dealer, as i did with my latest car they made a provisional order to secure the car i wanted in the colour i wanted, of which there was only 3 available before my handover date and no slots to build one at all in the 3 months. Then covid came along, so now my next handovers will be in june.