Originally Posted by egor
Some place them in the lower dash right above where your previous owner installed the current ones. You may need speaker spacers depending on the depth of new speakers you have. The driver side will fit with no issues but the wiper motor is on the passenger side and not that far behind the lower dash wall. 4" speakers are usually used. You will need to cut holes in your lower dash.
I've been wrestling with this for a while. Lower dash clearance is fine on RH, but you'll have about 1" of clearance inside the LHD b/c of wiper motor. Even with1" spacers which will probably snag knees, boots etc, you'll then have only 2". That may be enough for 4" speakers, but to get any appreciable sound you'll really need 5.25".
Lots of guys on the UK boards put then in the headliner (obviously, provided that you have a headliner) you have about 1.75-2.00" up there. Just need to use some type of sound deadening material like dynamat so you don't get vibration from the thin alum roof.
Just finished putting a set of component 5.25" rounds and recessed tweeters in the headliner. Out of harms way.