Our policy outright says that we shall not deploy a taser from inside a vehicle. Said that before we even got them.
Really supposed to strongly evaluate our decision to tase a running suspect as well.
Though my department is big into doing the right thing, for the right reasons. If you can articulate why it was the right thing, then it's been made clear that any policy can be disregarded by any deputy. It's about articulating those reasons in your report.
For our department it would be a matter of explaining that this was a felony suspect, was outside of the perimeter set up, was very fast, that the suspect was ordered to stop verbally and continued to run (this is the active resistance my department requires to use the taser). Would definitely want to talk about alternatives that were considered and why they fell short. Then what precluded sticking to policy (suspect was fast, stopping the car and getting out would have created too large of a gap to deploy the taser immediately, and catching up to the suspect on foot was very unlikely). Do that and you'd probably be good to go at my department, even though policy says no.