I'm going to replace the front door speakers on my '04 WRX. My car has a Rockford Fosgate component system, and I want to know if this was the factory installed premium sound. The reason is I don't want to waste my money on spacers if this is an aftermarket system and I already have them. It's too cold now to be opening up the door panel to see for myself, and I want to order the speakers today or tomorrow, but don't know whether or not to get spacers too. Thanks.
BTW: am I safe to go with any 6.5" speakers that have 4 ohms resistance? (same as current speakers) I'm thinking about going with Infinity Reference 6012SI.