Why does my car only start in neutral?

You mean like this?

Start here...

Adjust or replace your Neutral Start Position switch. Automatic transmission vehicles usually locate the switch under the dashboard, above the pedal cluster. Manual tranmission vehicles locate it on the shift linkage either outside the trans case or internally. If manual,,, it it designed to only start in Neutral with the brake applied as safety interlocks.

Remove and clean/lubricate your Throttle Position Sensor, found on the Throttle Body Injector Assemby, mounted on the Intake Manifold. The TBP Sensor may need to be replaced.

For $50/$100 you could also buy a code reader diagnostic scanner from Harbor Freight or your local auto parts store and run a scan of the engine management system. With 20+ sensors and data input points on a modern vehicle, there are several troubles spots I would also look at. Cleaning the MAP, MAF and O2 sensors may improve drivability/engine response.

The reason why is so the car won't start in gear and pose a dangerous situation. I agree with Bob on most counts but a lot of automatic trans. neutral switches are located on the transmision housing itself. They are generally simple two wire electric switch that breaks the connection between the battery and the starter circuit. They tend to wear out over time.

there se problem in wire which attached with gear................