Corrected entry: When Howard frees Phil from the police car and they run away, it is night. They then discover the ultralight aircraft, however it is daytime before they make an escape. Wouldn't the police have noticed he was missing by then, and considering the yard where the aircraft was stored is next-door, wouldn't they have been discovered long before escaping?
Corrected entry: At the end of the movie when Howard has strapped the Neutron Disintegrator to the buggy, he presses a button and the buggy sets off on its own. A few minutes later, Howard is in the driving seat and the buggy will not move until he hooks in the seatbelt. If that's correct, then why did the buggy go on its own before?
Correction: Because the seatbelt/ignition sensor won't allow the buggy to go if the sensor senses someone is in the seat without a seatbelt. When no one is in the seat, the sensor is over-ridden to allow for remote operation.
Correction: Phil tells Howard that it'll be dawn soon, so it's not as if several hours has passed. Second, when one of the cop cars pulls up, one cop says "they just spotted the duck and the kid", so they did notice Phil was missing by then and were looking for him (they were looking for both, but didn't know they'd be together). Third, earlier it was mentioned that Howard was armed and dangerous, so if one of the cops spotted him, he would certainly call for backup. So they were spotted before escaping, but not apprehended without backup. But even though they were so close doesn't mean they'd be found quicker than expected, especially if they hid when they saw cops approaching.
Bishop73