Using royal icing, make 22 tip 102 roses with tip 7 bases. Make 27 tip 101 apple blossoms with tip 1 dot centers. Make extras to allow for breakage and let dry.
With 4 in. round cutter, cut and bake 9 tires from cookie dough. Immediately after removing from oven, cut 6 cookies in half.
Ice 3 whole cookies together for spare tire and two sets of 6 half cookies together for back tires. Pipe three sets of tip 364 zigzag rows for bottom of back tires. For spare tire pipe one row of tip 364 zigzag and tip 4 white center. Smooth center with finger dipped in cornstarch. Add elongated tip 4 beads for spokes of tire.
Ice sides and window of car smooth with spatula. Outline silhouettes with tip 2 strings.
Outline window and top edge of car with top 4 strings. Cover car with top 16 stars, couple with top 13 stars.
Position tires. Cut nine 9-1/2 in. lengths of ribbon and position in random manner of spare tire. Pipe tip 1D banner over streamers. Pipe top 2 message.
Position roses and apple blossoms and pipe tip 352 leaves.