So, more on this second flat.
Driving home from work a couple weeks ago, I just crossed railroad tracks on a corner and as I was straightening out and accelerating, I glanced down at the speedometer to check my speed (try to drive by feel, but occasionally check myself). I looked back up and just caught a glimpse of something dark in front of the car as it disappeared beneath the front end. Before I could react, I hit the object, a 6" X 6" X 12" block of wood

. I hit the end of it with the inside edge and center of the left front wheel, immediately splitting the wheel nearly in two. Due to the weight of the car and the stiffness of the suspension, the car didn't jump or veer; the wheel ended up absorbing most of the energy of the impact. I quickly slowed down and pulled off the side of the road, not knowing what I'd find. I fully expected to see the fender all torn up from the tire. I got out of the car, and found a flat tire with a split wheel, no apparent damage to the car. Since there's no spare, I called my Dad to see if he could bring a wheel off of the C-Max. Of course, the bolt pattern is 2 mm larger, so that wouldn't fit. We ended up towing the Bolt back to my work, as it was a lot closer than home (rollback).
Calling around to different dealers, the price of one factory wheel ranged from $395 to $800. I ended up buying a full set of aftermarket wheels for $700, which gives me a full spare and two winter rims from the remaining 3 OEM wheels. I got the new wheels put on with 2 new tires (replaced both fronts as they were worn). However, the impact knocked the front wheels out of line, so I got it lined up.
For now, the Bolt is back on the road. The only remaining thing to figure out is there is now a mild rumble from the front end. I figured that it may be a wheel bearing.