why my car hardly vibrates when I put the gear on D or R while on N it's clear ?

Hyundai as a car manufacturer put a lot of free technical information and workshop manuals on line for Hyundai owners. Check out www.hmaservice.com lots of great information. I would look at the engine mounts, make sure the car doesn't have a misfire or vacuum leak. Hard to guess at what's wrong without being able to experience the problem first hand. If Hyundia's website doesn't have information that helps, There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online