Approximately the first 2700 cars, or DeLorean's with VIN's ending in BD000500 to BD003200, had hoods with gas flaps and locking gas caps. The same key used in the ignition and storage compartment behind the driver's seat unlocked the gas cap.
Once the gas flap hoods were superseded on cars with VIN's above 3200, the locking gas cap was no longer required and a simple, non-locking cap (110129) was used. These non-locking caps generally sealed better, and have been used over the years to replace the now no longer available, locking gas cap.
Dirt and moisture have a tendency to collect in the key hole on these and can make the locking mechanism difficult to operate. You will often find the cap in place but not really locked or latched, this can allow water and dirt to get in the tank leading to more serious issues.We recommend changing to the non-locking cap for daily use, as a corroded locking cap can strand you at an inopportune time.
Used locking gas caps are available on eBay from time to time, and occasionally your nearest DMC dealer may have a used one available, too. They can be re-keyed to match your existing ignition key; contact your nearest DMC dealer for details.
Written by James Espey, DeLorean Motor Company (Texas)
Revised 6/15/2016 DAS [added recommendation]