[Suomien]

Some dryer vent hose out the door will help, the $1000 vent box would be nice.

(and why are you *often* running the cobra in a garage? in california? with the doors shut?)

You don't say if you have windows in the garage, but the smell will linger after the car is shut down, so you might look into exhaust fan(s) that mount in windows. They make them to fit a pane, or to fit into glass blocks. Put them on timers tied into your garage door light maybe. Again, not knowing your architectural restraints, if a window fan(s) aren't doable, then powered roof vents (as long as they don't exhaust near upstairs windows or waft over a frequently used patio.

The obvious best solution would be a separate garage.