In advance: On waxed paper-covered board using royal icing, make 4 tip 24 swirl drop flowers for each cookie. Pipe tip 2 dot centers. Make extras to allow for breakage; let dry.
Cut cookies using car cutter; bake and cool. Outline car and window areas using tip 3 and full-strength color flow; let dry. Flow in car using thinned color flow; let dry.
Using royal icing, pipe in wheels with tip 7 (smooth with finger dipped in cornstarch). Pipe tip 7 outline running board and wheel wells. Add tip 3 dot hubcaps and headlights. Pipe tip 3 curving outline streamer; attach flowers.
For disc candy faces, pipe tip 2 dot eyes, outline mouth and pull-out hair.
For veil, roll out white fondant 1/8 in. thick. Cut a 3 x 1 in. wide piece, narrowing to 1/2 in. wide. Attach veil with dots of icing; attach heads in window. Pipe tip 3 zigzag crown.