I don't like the placement of the powerlock button. It's akward and hard to press.
I don't like the cup holders either. It's pretty good for large paper coffee cups, and I never had a problem with it because I only drank coffee during the winter, but one hot day recently, I put a can of coke, I step on the gas a bit hard, and bam, coke's all over my work and seats and pants and, well, everywhere. I liked the VW cupholders.
I don't particularly like the seat fabric either. The black is nice, but I don't like those little dark blue patterns. It's tacky. I'd prefer it all black, or perforated black cloth for a sporty look.
I hate the crappy fake carbonfibre trim. That's so lame!!!
The thoughtfulness of Mazda putting in adjustable height on their seats are nice, but it's not adjustable enough for me

Ah, I'm picky, but, you asked for it!
Well, that's all about it, it's all relatively easy to withstand when compared to all teh problems I had with my VW Beetle *shudders*
OMG, can't believe I forgot the ultimate worst part of the P5...
THE AUTO SHIFT KNOB IS SO DAMN UGLY!!! It's so freakin' tall and skinny and, well, generally ugly! Mazda took steps to ensure everything about the car is nice and sporty, except this POS! It looks like it came outta a Corolla ! *shudders*. I wish we could have a semi-auto like a BMW. Everytime I ride my dad's 323ci I wish I had the same autoshifter as his does! Sooo comfortable, so nice, sooo perfect.