Does anyone have any install pics of 6x9's in rear panel using an MDF adapter? I'm struggling to work out how it's done due to the shape of the panel not being flat.

There are some on the forum:
https://www.fiatcoupeclub.org/forum/ubbthreads.php?ubb=showflat&Number=606297

I did mine recently. I had to drill two holes for each speaker and used sound deadening tape to seal the hole. I did not make a mdf frame.

Thanks Jaaps, I'd found that thread but wasn't sure that the speakers would be twisted by the shape of the bodywork.

My hand has been forced slightly in that the front speakers I've bought will be too big so they're going in the rear now.

Back to the drawing board!

Mark.

A 6.5" speaker on an mdf mount sits very nicely in the lower aperture behind the trim and finish the area off with sound mat or flashing tape. Definitely makes a big difference.

I mounted mine exactly like that and no twisting, but you need to fill the holes with lead tape or something like that

Just incase anyone ever wanted closure to this one, I went with standard sized speakers in the standard location.

The rear quarter plastic is thick enough and has enough curves to be strong and have 'little' vibration. Plus the angle of putting the speaker in the metal body means it's firing at the wrong angle and firing into the rear quarter void. I felt the standard size and location would offer best results.

Spent a fair amount of time and money on vibration damping and sound deadening and a new set of speakers for the front. Rewired the entire system, amp and a teeny sub.

The sound is amazing, it's brought to light a few rattles that need sorting now. But it's the same thing as bhp, I'm already plotting a bigger sub and amp to match the quality and power of the main cabin speakers.