mb quart or diamond?

Like you said, I don't think you can go wrong with any of those choices.  75w should be great.  I have 50 going to the woofer, 50 going to the tweeter, neither seem to be starving for more. 

Which brings up another point about the quarts that the salesperson might not tell you.  The passive crossover is setup so you can bi-amp your set.  So, if you ever decide to get a dedicated class d sub amp or something you can feed all channels of your 4-channel amplifier to the quart component set.  This way, you can fine tune the time alignment, set levels, and eq separately on the tweeter and woofer.  I've enjoyed being able to this.

MB Quart with no doubt. The second I saw your vehicle was a convertable it screamed at me, then punched me in the head and said you idiot, I am a convertable and have a large amount of wind noise and nothing to keep the sound in. Top end is the first thing that you lose in the audio spectrum, even quicker in a convertable where this sound is not contained. The pure titanium tweeter at least is going to be able to provide some degree of reasonable output under these conditions. 75 w rms of power is lots but more might be better

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that is kinda why I chose components, I can direct the tweeters to ear level.

With top down, at 100+, I know I will lose everything (including the sub in the trunk).  But 90%of the time I have top up.  Car is still new, so not much sound loss (more than a sedan, but not too bad).

Do you think a x4 amp is the way to go? 1 pair of 216's + 1 JL 12w3 d2

d

btw, that was a great way of telling me I am an idiot worrying about sound quality in a convertible.  I like it!

I figure, start with high quality, lose a bit, still not too bad...

Tweeter mounts for a Camaro???

Rain here too.

Just listened to the MB's.  Both sound great.  Probably go with the MB's.

Sighs - looks outside at rain some more - I'm sick of waiting for it to snow. Just snow and let me get to work already. ^^^^ This is some good advice on the amp choice, some of the 5 channels can be bridged to 3 channel mode, doubling up on the front end and in some cases the sub channel is 2 ohm mono stable as well. Consider this great recommendation.