Subaru 555

Hi guys, am in the same predicament only I am trying to change the 4 door speakers in my 99 classic Impreza. I bought four 5.25” speakers and they where to small. So I then went on to Halfords and bought what they had listed as vibe 6” speakers and they arrived only for me to find out they are actually 6.5” ? do any of use know if 6.5” will fit in the front doors with spacers and what about the rear doors. Think I seen someone say they are 4” will I get 6.5” in the rears ?