Hello,
Im thinking of a pair of Pioneer TS-G1045R. They are 4" and relatively cheap at 40$ at SCA. Anything better and are they going to fit?
 
Regards,
SteveB
 

Hey steve,

These speakers more or less fit, but it depends how much the speaker grills have warped from the sun. Sometimes you can have a clearance issue between the centrally mounted tweeter and the cover.

Also the mounting holes dont all line up nicely, i think 2-3 will line up depending on which side. Best option is making a thin ring to adapt the holes properly.

I put the older version (yellow Kevlar coloured cones) of these in the dash speaker locations. 
 
https://www.jaycar.com.au/4-kevlar-coaxial-speakers-with-silk-dome-tweeter/p/CS2400
 

And in the end I ignored all good advice and went for a set of Sony xsfb1030.
https://www.jbhifi.com.au/gps-car-audio/sony/sony-xsfb1030-10cm-3-way-in-car-speaker/762707/
 
Was I pissed off that the "was 50$, now 40$" price on the Pioneer TS-G1045R expired the next day. Yep.
The sonys "was 69$ now 39$" a few days latter...........
 
But best of all, the height of the tweeter stack is around 3mm lower than the pioneers so theres clearance to the covers. The mounting tabs are perforated so you can easily discard the two that are not required and bend the one that sits on the Unut to the correct angle with simple tools and little risk of distorting the basket.
 
Easy to fit and sounds quite a bit better than I was expecting from such a little speaker set.