Fixing the front bumper and grill, found a couple of very helpful youtube videos. The key is to remove the front wheels!
Changing the grill. You can find one on eBay for a litter more than 100 bucks. A British guy also show video. This is better.
Deal the problem with no-start
This is a good link with fair amount of details My son finds this one, which is also good! Here is a post on testing the coil, another one here, and, we've got a smart guy who uses the paper click to test the voltage. Check misfire here, and it shall be dealt with before the problem gets worse. Check Miata coils. After all these research, it turns out that the simplest fix is just to replace the battery. We learned to have differentiate the sounds of "no start" vs. "with crank but no start".