My e36 316i VIN is AC66587. l get the wrong car when l run it thru decoders.It is supposed to be a 1998 model.

The serial number AC66587 is not valid.
Press & hold the Check Control (CC) button in ur instrument cluster. Turn the ignition to 'Run' but do not start the car. Release the CC button.
The cluster will now do a self test (do not turn ignition off until the test is complete & all gauges return to 0). In the CC display it will show the last 7 digits of ur serial number which should also be on a sticker on the doors, trunk lid, hood, fenders, & transmission. The CC number should match the number on the dash which should match all of the other serial numbers. If they r missing or mismatched ur car has been tampered with.

Benztech, l got this:
Chassis numberAC66587
Vehicle codeVC92
SeriesE90
Model330d
Body typesaloon
Catalog modelECE
Production date2004 / 08
EngineM57N2
TransmissionUnknown
SteeringRight
CatalyzerYES

And this using the ETK:
ERROR: VIN AC66587 Not Found.

l typed in my BMW software. IT says it is a 99 316 Saloon with a mechanical transmission. If you can find the prod date sticker. It should be in the left front door jamb. Anything built after July will be the following year car usually