Although there were not typical "yearly" updates to the De Lorean, there were several changes that were made to the DeLorean during production. The most visible of these changes related to the hood style. Click on a thumbnail below for a bigger image.
Side Bolster - There is nice bolstering (or whatever you call it) in the DeLorean. Not only does it give you a place to rest your arm while driving, but lives not just on the door, but also next to the seats. Unfortunately, in early models, this bolstering was bolted on and had a tendency to pull away from the rest of the interior. Later cars were changed such that the bolstering and the interior trip were now one piece. Problem solved! (Have an earlier car with this problem? E-Mail me for some tips)
Foot Rest - As an addition to later cars, a foot rest (in the form of an unusable pedal) was added to the cars to help prevent fatigue while driving.
Wheels - There was a change in the wheels on the DeLorean. The look stayed the same, but the coating and coloring of the wheels changed (with these changes also came color changes to the wheel caps). Early cars had gray wheels with gray center caps, later cars had silver wheels with black center caps (the black center caps have the DMC logo done in white).
Side Mirrors - Although I can't tell the difference, when I purchased my DeLorean at DeLorean Motor Company Stephen Wynne assured me that there were slight changes to the shape of the side mirrors in the De Lorean.
Radio / Clock - The De Lorean came stocked in 1981 with a Craig. Since the Craig did not have a built in clock, there was one installed in front of the gear shift. Later De Lorean's switched to an ASI stereo, and due to the ASI Having a built in clock, the DMC clock was removed.
Antenna - What good is an AM/FM radio without a good antenna. As many early DeLorean owners found out, not much. Early 81's had a windshield mounted antenna....and from what I hear, it wasn't much good. The next antenna was a front fender mounted antenna. Not bad for reception, but many people thought that it detracted from the De Lorean's beauty. Many people have retrofitted their early cars to the final antenna; a rear mounted power antenna. When retracted, you wouldn't even know it ever existed (unless you knew where to look).
Sun Visor - At some point in the De Lorean's life, the sun visors were "flipped." My car has the vinyl part next to the roof (when up). In later cars, I believe the reverse is true.
Door Guides - The DeLorean doors usually close great (while the car is level), but had some problems early on when the car was parked on an incline. To help guide the doors down to the striker pins, Door latch guides were added as the result of a service bulletin. These are simply metal pieces with a wedge shaped groove in them to guide the door down into the proper position.