What are your experiences with buying a brand new car?

I purchased a brand new car from a dealer almost two months ago and I thought I’d ask how other people’s experiences went. My car is a 2011 Mazda 3, stick shift with just the 2.0L straight-4 engine. My experience thus far is as follows:
-I ended up going with a new car over a used car (in the 5 year old range) because I was able to get an interest rate of 0.9%, so over the course of the auto loan I’m paying like $500 interest. Combined with the knowledge it would be 100% covered for 3 years or 30k miles (as opposed to rolling the dice on a used car) made the added cost worth it.
-Thus far I haven’t noticed any dings or dents, which I’ve been told the first one is a huge upsetting event, but I have confidence I’ll live since its not a Ferrari or something.
-I’m getting right around 30 mpg, which is what I expected and I’m happy with it.
-I’ve put 4600 miles on it in under two months (thankyou work) and its run pretty well. Though sometimes I am starting to notice the noise of the serpentine belt spinning, somewhat pending weather conditions.
-I’ve kept it pretty clean, going through it with a fur roller (two pets) and not eating in it, armor-all, etc… Wondering how long I can keep that up.
-The tires are some basic generic brand, I’m thinking I’ll replace them in the 10–20k range pending how the treads are holding up, so far so good.
-It has an aux-input so you can hook an mp3 player up to it, and I bought a used iPod with like 30gb storage and dumped my computers music library on it for car trips. Unfortunately the battery on the iPod dies quickly (its a refurb so I should’ve been expecting it). I can charge it using a car adapter I have as I use it, but the charger gives a feedback that goes all the way through the stereo cord and you can hear it in the speakers.
-Changed the oil with my brother once already. Put in a heavier weight than recommended and I think I’m noticing it slightly in the fuel economy, but still happy with it.

Overall I’m happy with the car thus far. I’m wondering how my first (if any) experience with the dealer will go if I have to get something repaired under warranty. Also wondering what I can expect long term, past the warranty. Its my first ever brand new car, so I dunno what to expect. Can you tell me your experiences with your new cars (where you’re the first owner)? How did it hold up, how were dealer dealings, would you buy it again, would you buy from that dealer/automaker again? Doesn’t have to be as thorough as mine but curious.