The day after I bought the car (that would be 19 September for anyone who suffers from attention-deficit disorder. BTW you are probably not married if you do) I did a few small things. Put the wiper arms on correctly (PO had apparently painted them and didn't put them back on the right side), did a massive stickerectomy under the hood, set the tire pressures and generally just drove her. I only had a couple of days to do that before having to go to Dubai for a work-related conference. Talk about separation anxiety!
Over the next couple of months I did quite a few small things. Replaced the god-awful yellow hose kit with a black one, replaced the chrome gas filler door with a stock painted one (forgot to mention the car had one of those when I bought it, the wife liked it better than the painted one. Guess I need to sign her up for M.net). Put in a cargo net. Changed all the fluids using the magical Motorcraft synthetic in the tranny (I really like it), I found the oil filter was barely on there so it was a good thing I did that. Raised it by 13mm which corrected the majority of the grounding issues. Did my first autocross a few days later and had a blast. Got a performance alignment at a place in Cincinnati run by a guy who has been around for years, he didn't give me my final specs and I didn't think to ask for them, but he told me I had toe out in the rear (which went a long way to explaining the tail-happiness of the car. Besides my heavy right foot around corners that is). Installed some Hella Supertones but wasn't happy with them so switched to my usual Fiamms. I went all out and bought a stock hanger for the driver's side one so it would look stock.
When I was messing around with the horns, I discovered the driver's side headlight was missing a plastic spacer for the post that located the bottom of the light. Bought one of those to correct that issue. Someone along the owner's road had installed a bra which used snaps and they were still on the car, so those came off (and I found that the two at the front of the hood had been put on with screws that were just a bit too long, so I had two bumps from that). Flipped the passenger seat stopper around to get that precious extra inch of legroom.
One thing I did that merits some attention was install a factory 6 disc changer. Ha, I can hear you say, you couldn't get one of those in 2000 on a Miata. True enough, but you could get one on a 626. I was looking around eBay and noticed the plugs in the rear of that unit were the same as on mine. After some research I found out the bar in between my stock radio and cassette player was just plastic. So I bid on and won a radio. Guaranteed to work, but upon receipt I found that wasn't the case as the CD player wouldn't. There was a CD stuck in it for one thing. I got in touch with the seller, who told me to keep it and reimbursed me my cost (in other words, a stand-up person). I messed around with it and managed to get the CD out, found the eject button was messed up so using some plastic steel and silicone built that up. After that it still didn't function. On to the next step.
In case you didn't know, Mazda uses modular radios. This means you can swap bits around to get where you want (for instance, my wife's RX-8 came with a single CD player. I bought a beat up 6 disc unit, changed over the CD player and voila!). I knew this was the case with vehicles after 2001 but not earlier. I was able to find a 6 disc radio from a 2000 Tribute on eBay (listed for parts as it had a rattle inside). When it showed up, the rattle turned out to be 36 cents in loose change (someone's kid probably got a whipping for that one). Swapped out the changer unit and the faceplate, put it in the dash and it worked like a champ. Sure it doesn't play MP3s or have a slot for a memory stick, but I don't have to juggle CDs all the time either. Plus since it's factory with Mazda all over it, I don't have to worry about someone prying it loose.