6. The timing of breaks.
If your Chihuahua does not do well in the car, it'll be common to want to get from Point A to Point B as quickly as possible.
And alternatively, if a dog that previously did poorly is now doing much better, they'll be an urge to keep going while things are good.
However, dogs that feel nauseous need to have breaks. And for the dogs that handle the car better by implementing the previous methods, there may still be a 'breaking point'.
Therefore, if your Chihuahua is getting car sick, take a break every 20 minutes.