[–]Hayden Baker•
I've been using a great site for years. It's called WillTheyFit.com. You can measure off you current wheels to see how much further out you could poke them and how far in the can go as well. It's a great tool to actually visualize how the wheel will sit compared to your current wheel.
I think a lot of it comes down to the wheel offset. You may want to do a google search and see if anyone else has gone with the 15x8 wheels and what sort of hurdles they came across. Alternatively, you could start going through some of the heavier modified Miata's on here using the search function.
I do vaguely remember coming across a wheel size calculator thing that showed if a wheel/tire combo would fit your car or not. I believe it was even geared towards Miata's but I haven't been able to find it. http://www.willtheyfit.com/ might be your best bet in that aspect but I'm not sure.
[–]Daniel Rush•
Alright thanks man! If it helps any, my offset is like 22 I think? Not sure. Have to check.. thanks tho
[–]Alonso Marrufo•
I don’t own a Miata so I’m not too sure exactly but I have a 00’ Civic with 16x8 offset +20 and I had to roll the rear quarter panels because the tires would run and I wanted to go lower. My cars not slammed but it is fairly low. Hope this helps
[–]Hayden Baker•
You could trim the factory cover to allow the speaker to poke through and use a stretchy speaker fabric glued to the inside of the stock piece to cover the speaker
[–]Daniel Rush•
So cut the factory grill to let the tweeter stick out and glue a stretchy fabric on the inside of the grill and let the tweeter push against it?
[–]Hayden Baker•
Yup. Or no fabric of the speaker looks good
[–]Jessica Pomerleau•
Maybe some sort of galaxy fabric could be cool?
[–]Wilson Oberholzer•
Going by the looks of that you could build up a wooden surround piece that bolts to the door and then cover that in a stretchable fabric if you wanted it to look really clean. Another option would be to find some properly sized speaker "grills" to cover it or make your own from some cheap mesh.