Downforce

No — all bid cards are returned to players' hands after each bid and can be used again in later auctions (Rulebook p.3).

You move every car whose color appears on the card, even cars owned by other players, unless a player has the Cunning power which lets them decide where their cars move on other players' turns (Rulebook p.4; Cunning description p.6).

White cars are wild and you may choose any color car to move except a color already printed on that card (unless you have the Unpredictable power); you may even choose a car that has finished or is blocked (Rulebook p.4).

Cars cannot move through other cars and must be moved the full amount if possible or as far as possible if not; if there is a legal move you must move the car, but if blocked it simply loses the rest of its movement (Rulebook p.4–5).

There are three betting lines on the track: the first time any car crosses the first line (after that card's movement is resolved) each player secretly marks which car they think will finish first, and the same betting step happens again after cars first cross the second and third lines (Rulebook p.5).

If you have more than one power card after the auction you pick one to keep and return the others to the box, and the power you keep applies to all of your cars (Rulebook p.3; power rules p.6).