How about this donk for an example of tacky decor? Of the automotive variety. The baroque over-ornamentation. The oversized wheels that look like they belong on a Well Fargo stagecoach. The calliope of horns under the front bumper. The metallic baby shit brown paint.
I know that donks emerged from one of Those Subcultures Which Must Never be Questioned or Criticized, but I can't think of any other word to describe this except tacky.
Wait a minute... the word "silly" does come to mind.
Lindy