Conclusion: I put 4 of them in my 89 325I convertible. They didn't really fit correctly, I had to trim some interior panels to make them fit...but they sound amazing...hooked up to a Sony 2 channel amp..great bass and crisp highs :-) definitely would recommend to anyone.
Conclusion: i upgraded my rear speakers in my 08 scion tc with these alpine ones. i also upgraded the front with the alpine speakers too. once i installed the system these speakers really worked great! they have amazing highs that come in crystal clear. the mid is just enough to compliment the entire system and the result is fantastic. i get compliments inside the car all the time at how well they work and make it able to hear the music and not just the bass.
Summary: Great seller!!!! I order the Alpine SPC-13c a week before Christmas. When I finally had a chance to install it (someday in Feb.), it was completely the wrong size. My car insert was 6x8, and the speader was 5-1/4. Stupid crutchfield.com told me they will fit. Oh well, I contacted the seller. He said it was no problem, just send it back and he'll send me the right size. The speakers arrived less than 4 days. He kept in contact with me until the transaction was complete.