For me, less is more....
When mine have been pressed into service, they've just had ribbons on the front and flowers in the back. Nothing else - the bride's the star.
Agree with the comment on carpets, etc. Also worth having a chilled bottle of champers and a couple of glasses in the back.
Im trying to keep it simple...
im not sure about the champs, as they will be driving away, as a couple in it... drink driving never a good thing