The smell can be overpowering at times but I use very little of it and air out my car afterward. MY reward, when people step itno my car they are like how long have you had this car? Still has new car smell (haha starsky and hutch, c'mon, due it, new car smell!)
An H2 will have lots of surfaces to treat so I would get 2 bottles to save on shipping since you may use it more often that I do. Even with treating my sneakers often (haha yeah nice smell to have follow you around too!) I barely knicked my supply of Z-9/Z-10. If I ever run out, my Z distributer is only a short drive away (think less than 15 minutes.)
A good offense is a good defense too. I do not let people eat in my car, let alone have an open drink. No coffee cups in my cupholder, just my phone and flashlight. I keep gallon sized zip-loc bags in the car in case the family wants some KFC, so I just take the food and put them into the bags for safe, effective, greatly reduced smell transport. Also good when someone wants to get sick by my driving (you never know, but everyone that seems to be riding in my car falls asleep by the boringness of it.)
So it may put you in a trance, but currently Z8 owns my nose....