How about that:
During race player have 3 arrays of weapons: shooting, help & mines category. Weapon pad hit by player draws one of 3 colors (pink{shooting}, green{help}, blue{mines}) and weapon selection in player's array sets itself on first slot of category according to WP color. If player will hit next WP without using selected weapon the selection moves one slot further in same category. As for elements they are placed in categories according to their usefulness which we will decide when weapons will be accomplished. What u guys think?