I work as a service manager in an independent repair shop that specializes in "foreign" makes and models. Here is my opinion:
1) There are certain cars for which extended warranties pay for themselves (VW/Audi) being the prime example. Most Asian cars have so few repairs needed that it rarely pays for itself.
2) Most extended warranties expire before modern cars need much repair. In my experience Nav systems & CD players rarely have problems in the first 100K miles. I can't speak to DVD players. But make sure those are actually covered in the warranty.
3) Extended warranty companies are in the business of making money and they are not all created equal. Some will not cover diagnostics or they will play around with definitions of covered versus noncovered components. Others are very good and don't play a lot of games. Research all reviews on the company.
4) If you have an extended warranty, it can increase the time it takes to repair your vehicle. The warranty company will usually send an inspector for more expensive jobs (and even some smaller jobs if you have made more than one claim) and that can easily add 24-48 hours to the repair time.
5) Make sure you have a trusted mechanic read the entire contract for you before you buy. A repair shop that has worked with a lot of different warranty companies learns what tricky language the warranty company can insert into the contract to avoid having to pay claims.
6) If you buy the warranty, be sure to follow all manufacturer recommended maintenance and keep all the records. A warranty company can refuse a claim if you are not maintaining the car properly or can't prove that you are.
Hope this helps. Enjoy your new car!