Sixth Generation Celica Chassis Codes

The chassis code on a sixth generation Celica can be used to identify what kind of Celica it is. It can be useful sometimes, because refering to Celicas simply by the type(GT, ST, etc.) can be misleading. For example, the USDM Celica GT is powered by the 135 horsepower 5S-FE engine, while the European Spec Celica GT is powered by the 180 horsepower 3S-GE engine. If you were on the phone with a tuner company in Europe and you just said "I drive a Celica GT.", and had them send you, say, a header for your car, then they might send you a header for a 3S-GE engine, which would not work for your car. This is why chassis codes are a better way to identify which kind of Celica you have.
The chassis code can be found under the hood on the firewall on sixth generation Celicas. It's a four to six character combination of letters and numbers. A couple example sixth generation chassis codes are AT200, ST202, and ST205.

{AD} The first character in a sixth generation Celica chassis code will either be an "A" or an "S". This letter represents the engine family of the car. "A" would be for the A family of engines, such as the 7A-FE, and "S" would be for the S family of engines, such as the 5S-FE and the 3S-GTE.
The second character represents if the car is front wheel drive or all wheel drive, or rear wheel drive. This character will be a "T" if the Celica is front wheel drive or all wheel drive, and an "A" for rear wheel drive Celicas. So for the sixth generation Celica, this character will always be a "T".
The third and fourth(Or just third for rear wheel drive Celicas) characters represent the Celica generation. For all sixth generation Celicas, this will be the number "20".
The fifth(Or fourth for rear wheel drive Celicas) character represents the type and engine of the Celica. Here are the codes for the sixth generation Celica:
0 - FWD - 7A-FE (USDM ST)
2 - FWD - 3S-GE / 3S-FE without AWS (JDM SS-I, SS-II, and SS-III)
3 - FWD - 3S-FE with AWS (European GT / JDM SS-I)
4 - FWD - 5S-FE (USDM GT / Canadian GT-S)
5 - AWD - 3S-GTE (European GT-4 / JDM GT-4)
The sixth character is only on sixth generation Celica convertibles, and it is a "C" representing that the car is a convertible.