When the car turned and basically tried to play chicken with me I would have drawn my gun while getting out of the way, the latter being most important. When they stopped and bailed out they would have been met by Mr. gunpoint and I would have asked that police be called by my partners. If the thugs responded appropriately, stop and retreat, and if they weren't armed, I would simply make the best witness possible.
The second part likely wouldn't have happened due to LE presence however if it did, I would be forced to draw and in this case defend my vehicle. I know its not the wisest choice however having the advantage of gun vs ball bats allows me to save some money in copays.
My life is worth more way more than the copay, the bad guys live not so much. Attack a man with a bat who is armed with a gun and get what you deserve.