I remove all the dirt, etc., out of my Client's vehicle Interiors, so the only scent left is a Clean Scent and the natural scents of their Leather interior..
I hate those little trees, etc., junk that makes your eyes water and kills your sense of smell.
If I find them in a vehicle, I put them in a good sealing plastic bag/s and return them to the Owner that way..
Long ago I understood that any scented stuff is there because you want to mask the smell of something else. So why not get to the source of the smell you don't like, and eliminate it instead?
Some of the better products out there will have a little scent to them that dissipates in 24 hours, etc., and those are nice too.
A really nice one that used to be sold was Einszett Cockpit Classic in a spray can. It was made for "Interior Fittings"- all the plastic parts. Anti Static, dust control, satin finish.
Think the only place you can find this if any, is Einszett in Austin Texas..
Good luck with your scent research !
Dan F