In the desert, Michael walks at least 10 feet away from Max to retrieve his shovel. But when he turns and walks back to resume digging, he only walks 2 or 3 feet. Michael's position in relation to the parked car and a distinctive white shrub further demonstrate the discrepancy.
When Maria broke up with Michael they discussed how everything alien had been going on for three years. Maria was already driving when she discovered their secret. Which would make her 19 at a minimum. However, when Maria speaks with the music producer she states she just turned 18.
When Maria and Liz are talking on the bench, patrons in the shop behind them are pointing and staring out of the window directly at the cameras.