My wife's '06 (yes really) has a donut mount for said spare in the trunk. Would this mount also act as a rear strut tower support? The attachment points seem the same for any aftermarket strut tower support. Yes it seems beefy enough to add copious amounts of weight. But she wants to keep it in there.

 

It does add a little bit of support but not what a aftermarket one would in my opinion. What you will really notice is if you get a spare wheel/tire and mount it. You can really feel it in the twistys. I have experienced both and you can definitely feel the higher weight.

 

I just bought if for her (used of course). She traded in an '04 automatic 4 spd for the '06 MT. Her and I already have noticed the buku power difference. I am just debating on doing away with a real spare or not. I dont know about Mazda's answer to a flat with the fancy fix a flat option. She wants a sub as well. Which in reality would most certainly do away with the donut. And probably leave an after market strut tower support out of the question as well. Need all the room you can get with even a small sub woofer. Thank you for the input.

 

You bet Mario.

Its my wife's daily driver and she wanted the piece of mind of a spare.
It took about 3 months of watching the "For Sale" forum to find a guy here
in SoCal that was getting rid of the spare for a reasonable $100. Dealers want
$350 for the complete setup. ouch!!

 

If you dump the spare, get a large can of fix-a-flat, I like the SUV size. I have read, here and other places, that the Mazda kit makes the tire unrepairable. With fix-a-flat, they just charge an extra $10 or so to clean up the mess.

TMPS will let you know if a tire is going down. Running a tire low is usually what destroys them beyond repair. The only other way you can get hosed is something catastrophic that rips the tire apart. Then you are out of luck. I looked for a spare, then went without one for the extra trunk space. There are more and more cars out there that do not have a spare.