The short version
- Chassis number: a plate on the nearside, visible through the windscreen, and stamped into the chassis behind the offside front wheel.
- Turbo engine number: on the side of the block at the rear, facing the bulkhead.
- NA engine number: stamped on a flat surface on the side of the oil filter housing.
- Build number: the last four digits of the VIN. The register is keyed on it.
Chassis number
A 2006 buyers' list said it is on a plate on the nearside, visible through the windscreen, and stamped into the chassis behind the offside front wheel. The same list mentions a sticker near the driver's door catch. The chassis and engine numbers on the V5 should match the car.
Engine number
- Turbo (Z20LET): on the side of the block at the rear, facing the bulkhead where the engine meets the gearbox. A 2013 list said it is on the left as you look into the engine bay, and that it is awkward to check.
- NA (Z22SE): stamped on a flat surface on the side of the oil filter housing. The photo below is from the Vauxhall TIS.
Parts catalogue entries sometimes change at a particular engine number. For example, the NA ignition module 12580537 applies from engine number 11334391 (see Coil pack: faults, testing and replacing).
Build number and VIN
The build number is the last four digits of the VIN. You need it for a car history check, and the register uses it to find a car. You can search for several at once, for example 612* for every build number starting 612.
Speedster number
On a Speedster, the Speedster number comes from the dash plate. It is not the same as the VIN build number, and the register keeps them in separate fields.