Driving in traffic, gently passing, running 85-92mph in a 70 in my E46 M3, top down, so it's windy. Earbud connected to the Escort 360. Gradually, I come up on a newer BMW 745. Tinted rear window and custom license plate (referring to his car model) tells me that he's intentional about driving. Still, he's going just a bit slower than me, and I want to get around him. But I hang back half a dozen car lengths to give a respectful leeway, and to avoid any challenges. It is 11:30am on rural freeway, and traffic is light. Bright, sunny, no wind. We work through a group, and the road is wide open for as far as I can see. He begins merging right, and I put on just a touch of respectful throttle. Despite my best effort, the challenge arrives anyway. I can smell his clumsy full acceleration before my depth perception detects any increase in his speed. In a heartbeat, I press the clutch, leaving my foot on the gas, same pressure. Out of sixth, into fourth, lift the clutch for a perfectly rev-matched downshift. My foot is fully off the clutch at about the time the accelerator smoothly reaches the floor. I'm guessing about 1 - 1.5 seconds have passed since I smelled the thick exhaust. The M3 hits 6500rpms and 4th gear takes it up to 8,000. The sound coming through the thin headers drowns everything else out. 5th gear takes me back down to 6800 rpms and I'm wide open throttle again. I glance down as I pass the 745 to see just north of 135mph. I reach down to hit the "all windows up" button - getting windy - and a car catches my eye on the oncoming freeway. It's the only car; those lanes are as empty as ours. I was distracted by the action, and wasn't watching. It is a black dodge charger - fully marked, lightbar above. I'm more than half way through 5th gear - I glance down - between 155mph and 160. "ZZZ ZZZ, K... Band" in my ear. Instant on K band? Clutch instinctively goes in, foot comes off gas. I spin my head round between my headrests and see the 745 driver as white as a sheet, stunned look on his face, 50 or 60 yards behind me. I check my driver side mirror: no lights on the Charger, yet. There's a full crash fence between the freeways, and I don't remember a median crossing since at least 15 seconds ago. That's a delta of over 220mph, that's a 30 second lead not counting braking and turning time... I glance back at the 745, still falling behind from my momentum and he's motioning forward, "GO, GO, GO." We're on the same page. Re-engage, wide open throttle again, and into 6th gear, somewhere. 170mph? I don't even know. I catch up to another pack, slow to 80, and am working my way through gently as the 745 catches up 15 seconds later. We work through; wide open again. He's 200 yards behind me when he zips off the first available exit ramp; certainly trying to turn the trail - nobody with a 745 has any business at that podunk exit. I continue on for 3 more miles, squeezing every bit of speed between groups or cars, slowing to 90 for the pass, then wide open once again. Then exit myself, working my way to the south. Eventually I circle back up home, and the car stays in the garage for a few days.