No it won't leak in the car. I would look into getting used ones in good shape from a junk yard or try ebay if you don't want to pay for new.

 

I need to replace the Lower seal for my passenger side. Just wanted to know if this is the correct one/side for the passenger. Thanks

http://www.infinitipartsonline.com/infiniti/g35/80839am92h/2006-year/base-trim/3-5l-v6-gas-engine/body-cat/exterior-trim-door-scat/?part_name=lower-seal&position=left