too many scents or too strong of a scent can cause headaches. might not affect you but your passengers might want to open a door on the highway and roll out to escape "new car smell".
I think new car scent is the best. I want to stab people with a rusty fork who open up a new air freshener and completely remove the plastic right away. Scent overload. You need to gradually pull the bag down.
As Munchy said, that shit can be intense. I ripped off a friend's black ice (don't fool yourselves into thinking it's a manly smell, it's terrible) and threw it out the window 5 minutes after he opened it and couldn't take it anymore.
Chemical Guys New Car Scent or Chemical Guys Leather Scent. Best thing is to spray 2-3 shots under the seat so the odor is absorbed into the carpet and slowly released for weeks to come. It also prevents the smell overload once the initial spray sets in.