My 1st car

I bought this car one month back. I did all the pre delivery check. Just one thing i noticed then that one live plant was growing from inside of the back door. I thought that it can not hurm my car. I purchead the car. Every things are okay. But now i found that one rat is inside the car. And it is starting eating plastics of my car from inside. I used rat kill, lal hit spray to kill the rat. Few weeks gone. I thought rat is dead. But again i noticed rats toilet remains. Again he started eating my car. I am not able to locate where he is hiding. When i start the ac, full car fils with rat smell. What to do? Any advice how to kill the rat.

I like my car. It is stylish, comfortable. No gear or body vibration. I have not checked the milage yet. Only one problem may be in my car. When i drive the car above 60kmph and the road is bend (roads left side is higher then the right side) i hear a big grrrrrrr sound. Like two running parts are touching each other. When road is flat the sound goes. What to do? I have driven my car 250 kms till now. Any body experiencing this problem ?