Anyone know if the scent is strong enough to kill spiders that may be living in the car? I read somewhere that chlorine bombs such as these may help.

It does kill spiders, but it took me several times to get it to work. Tenting the car with a car cover works best and then following up with a mint or pine scented car spray on the inside

does it help gasoline smell?

I used this after spilling gas in my SUV in 2016. I tried several other options first that didn't work. This cleared up the smell completely and 4 years later it has never returned.

will this kill mold spores?

Since I'm not the seller I'll give you my opinion, as someone who is has mold-susceptible genetics and the history of severe illness that goes along with that. I would absolutely give this a try given its cost....I have used hydroxyls and ozone in my vehicle successfully. What ClO2 likely cannot do is clean the AC duct system, even if the AC is running, if there is a "pool" where condensate collects as there was in my car. I subsequently found an angel who went into the duct system, filed down the edge of the "pool" so condensation no longer collected there, and I have been successfully using my AC ever since. My car is a 2005 and I'm still driving it.

I want to get this for my sons car who smokes but the reviews on it exploding are troubling. What causes it to explode and how do you avoid that?

Cl02 is combustible at a specific temperature, relatively not possible for normal atmosphere temperatures, but higher altitudes decreases the pressure and thus the temperature requirement needed for combustion. In normal uses at normal altitudes above sea level, unless your car is around 90 Degrees in sunlight, it shouldn’t combust because the concentration of Cl02 in this product is low for safe use. The smell is chlorine, and it’s not hazardous unless found in higher concentrations. Your nose may burn but the long term affects of this product are none. For Chlorine to have any long term affects, it has to be found in much higher concentrations than the amount in this product.