I'm thinking about installing an aftermarket stereo in my '03 SSEi.....and I've searched a lil on the internet for a dash adapter kit....but haven't really found much...i was wondering if anyone else has installed an aftermarket stereo in their 2000+ and can tell where to find a good adapter kit....

I kind of like the stock stereo though...but i want to put some subs and an amp in my car...so does anyone know if the stock stereo has the RCA outputs?

no it does not but here is an idea so u can keep the factory. buy a hi to low converiter or a pyramid sub woofer crossover. it connects to the rear factory speaker wires. and has rca'* at the other end connect set up your amp and you good to go

The "stock" head unit on an '03 SSEi should be a Monsoon system. The Monsoon head unit outputs are line level. That means they are the same as RCA outputs except they don't have RCA connectors. There already is an amp in the trunk (behind the rear seat).