So what do you suggest I do now.


[QUOTE=vlad_a;8885996]If the steering wheel is turned, the vehicle can still go straight.
There are many forces in play that the turning wheels have to overcome to make the direction change. If front wheels don't have enough traction, the vehicle will keep moving in its original path regardless of the driver input. Just like on old cars, when you lock the brakes, the steering no longer works.
AWD and 4WD vehicles are more prone to understeer because all 4 wheels are trying to move the car forward. A 4WD vehicle with its differentials locked will only go forward.

This appears to be different from OP's situation. His car unintentionally changed the direction on him and yanked the steering wheel at the same time. The steering wheel is directly connected to the steering rack, so it is possible to hold it in place. However, if it happens unexpectedly, one could certainly loose control of

 

I would suggest contacting your Lexus dealer for a loaner. Surely they will provide one.

 

Ditto! If Lexus has your vehicle, then they should provide you with a loaner.