Microphone recommendations?

[MrMickS]

I've been making videos of my drives for the last year or so and sound is still an issue. I want to pick up the exhaust noise and am looking for a microphone and mount I can use to do this.

I have been using a rear mounted GoPro, which works to a degree but picks up a lot of road noise if the road is damp which takes away from the sound I want. Here's a sample of what I'm talking about: https://youtu.be/qmhJdJF6lwE?t=5

Alternatively if anyone can recommend any Mac software that I can use to reduce the road noise but keep the exhaust note I'd appreciate it. I've tried all of the filters in Final Cut Pro X but they don't seem to do it. I'm happy to spend a little cash if it will do the job.