Basically, it is going to depend on the conditions you can maintain in a car, where I live in the great basin temperatures get to 100+f and temps in a car can easily get to 140f which will pretty much kill anything green...
another challenge would be physical stability, something like a sansavaria would be pretty hardy through a pretty good temperature range, not need to much water, but not appreciate being "jostled"...
the one thing that that study failed to study (at least this was my takeaway when a read it) is the soil... I suspect a fair amount of the metabolism that they saw was through the soil associated with the plants and not from the plants themselves... so you could with much less effort keep some soil microbes in your car... you could even mix activated charcoal to help sequester hydrocarbons, and the soil oxidizing bacteria could eat them...