After Karen gets into the jeep and is talking to her father about how strong she is, it's daytime. In the a long shot when the jeep pulls away to go to the woods, it's nighttime.
Towards the end of the movie, the leprechaun tears through the soft top of the Jeep. A few seconds later an overhead view is seen, and the soft top is fully intact. An interior view is shown after that and the fabric can be seen hanging down once again.
This movie is supposed to take place in Massachusetts around St. Patrick's Day yet all the trees are in full bloom.