A look at the most important thing each team needs to do or change as we enter a new calendar year and Formula One season, starting with the bottom five from last year's championship.
Sauber
Build a car worthy of the Alfa Romeo name
Since the introduction of the current engine regulations in 2014, Sauber has dropped from the status of solid midfield runner to that of perennial backmarker. The financial realities of basing a team in Switzerland have hit hard and had it not been for a change of ownership in 2016 the team may have disappeared from the grid altogether.