Don’t postpone the decoration of the car to the last day. There are certain preparations which need to be taken care of before you arrive at the event. Don’t make the mistake of applying too much adhesive tape. The decorations are for one day only, after which they need to be removed.
It is not recommended to use balloons for decoration. They may come loose and leave a gap in the structure.
Don’t choose too many shades of color. Two shades will do the job. Of course these shades of color should match the color of the car.