| Acura | On a label inside the driver's door jamb. The code should begin with a letter. |
| BMW | Inner strut tower on the driver or passenger side of car. The code should contain three numbers. |
| Cadillac | Under the trunk mat on a label. Should be a two-digit code ending in U or a WA number that is four digits long. |
| Chevrolet | Under the trunk mat on a label. Should be a two-digit code ending in U or a WA number that is four digits long. |
| Chrysler | On a metal tag in the engine bay on the radiator support. The code is three characters. |
| Dodge | On a metal tag in the engine bay on the radiator support. The code is three characters. |
| Eagle | On a metal tag in the engine bay on the radiator support. The code is three characters. |
| Ford | On a label inside the driver's doorjamb. The code should be two digits, normally two letters or a letter and a number. |
| Geo | On a metal tag in the engine bay on the firewall. The code should be two digits ending in U or a WA number that is four digits long. |
| Honda | On a label inside the driver's door jamb. The code will begin with a letter. |
| Hyundai | On a label inside the driver's door jamb. The code will be two digits. |
| Infiniti | On a metal tag in the engine bay on the firewall. The code should be three digits, normally two letters and a number. |
| Isuzu | On a metal tag in the engine bay on the firewall. The code should be at least two digits long. |
| Lexus | On a metal tag in the engine bay on the firewall. The code should be three digits always beginning with a number. |
| Mazda | On a metal tag in the engine bay on the firewall. The code should be three digits long. |
| Mercedes | On a metal tag in the engine bay on the radiator support. The code should be three numbers. |
| Mitsubishi | On a metal tag inside the engine bay on the firewall. The code should be three digits, always starting with a letter. |
| Nissan | On a metal tag inside the engine bay on the firewall. The code should be three digits, normally two letters and a number. |
| Plymouth | On a metal tag in the engine bay on the radiator support. The code is three characters. |
| Pontiac | Under the trunk mat on a label. Should be a two-digit code ending in U or a WA number that is four digits long. |
| Saturn | Under the trunk mat on a label. Should be a two-digit code ending in U or a WA number that is four digits long. |
| Subaru | On a metal tag in the engine bay on the radiator support. Should be a three-digit code, with the first two digits being numbers (the third may be a number or a letter). |
| Toyota | On a metal tag in the engine bay on the firewall. The code should be either three numbers or a number a letter and a number. |
| Volkswagen | On a label under the trunk or on the driver's rear wheel well. Code should start with an L" and be four digits long. |
| Volvo | On a label under the hood near the driver or passenger strut towers. The code should be three numbers long. |