Street Lights like nfs

I am creating a car game. I want to make some street lights that will be fixed at the foot path as in like need for speed or other car arcade games. When the car hits the lamps at high speed, i want it to fall without effecting the speed of the car much.

I have tried to create it using OnCollisionEnter and then when the car collides, the isKinematic option on the lamp rigidbody becomes false and the lamp is expected to detach i.e, the rigidbody of the lamp is non kinematic. It worked but when the car collides, the car reaches zero speed and then the lamp falls. If have tried on Trigger Enter but it is effective at slow speeds.