Hi,
To be honest I wouldn't.
Not just because it is taking the snake out of a properly controlled environment for an extended time for no reason but because the people at the car show cannot reasonably be expected to have prepared for encountering a snake.
What if somone is phobic?
What if the snake escapes or gets stolen?
There are just too many opportunities for it to go wrong and end up as seriously bad publicity for not only yourself but for the hobby in general.
You can do handling and encounter sessions but it needs a lot of pre-planning and approval etc.
If you are talking about having a booth offering that then talking to the car show organisers about what they would need would be the best start then discussing it with other people who run enounter sessions about the practicalities would be your best plan.
If you are going simply as a member of the public then it is all risk and no reward for the entire hobby.
Just my £0.0124568 ( adjusted for exchange rate)
dr del