Gunnerz, please clarify your thoughts so we can better understand a few important points. I want to start by asking you why you would compare these three vehicles? Are you looking to purchase a used vehicle, and you are in debate over these three? Secondly, I want to tell you that in '04, the Crossfire was only one model, not three like for '05 and '06. For 2004, you were getting the equivalent to the '05 limited coupe model (no convertible available for '04), which includes a leather interior, exterior and interior color choices, optional all-season tires, optional automatic transmission, optional navigation, standard silver-colored trim on the window surround and side strakes, and probably some other things. The "base" Crossfire was introduced in '05. Now, on to the comparison...I strongly feel that all three cars are very similar in terms of character. They all are small, nimble, and relatively light-weight vehicles with strong midrange power that makes the cars feel quicker then they really are. I have driven a Z4 3.0i, sport package, 6-speed manual, I have a '04 Crossfire with 6-speed manual, and I have been a passenger in a Z3 Coupe 3.0. Out of these vehicles, the Crossfire has the softest suspension set-up, making it more susceptible to body roll around corners, but all three have plenty of grip to have fun on the streets. The Z4 had very, very light steering, making it feel disconnected at high speed, probably due to the variable steering rack offered in that car. I prefer the Crossfire's weightier steering effort. The Crossfire got into it's torque band quicker than the Z4, but the top end of the Z4 was ever so slightly stronger. Like I hinted at earlier, these cars are all very, very similar, and only minute differences are noticed to those who really take notice. The seating position in the Z4 is much lower, the view out the window gives the sense that you are driving a boat b/c of the very long hood, whereas the Crossfire's outward vision gives the sense of less "car" in front of you (which this is true). I think the deciding factor between both cars, after price, is looks. Which one looks better to you? I'll tell you the Z4 was great to drive when it was soooo nice outside because of the aurora created by driving a convertible. The Z4 is more has more of a classic look, distinctively BMW. My only gripe with this is that it seems that "everyone" has a Z4. Who has a Crossfire? A Crossfire is much more rare. A Crossfire also has a more exotic, "what the hell is that" look to it. I love the last 1/4th of the car, from all angles. The roofline is very concept-car like, and combined with the big wheels, makes for a head turner beyond the Z4 since everyone has one. Oh, and both should be good on fuel economy, the Z4 having an onboard data center to tell you things like mpg, average speed, and other little things like that. The Z4 has a much larger aftermarket and better pedals to heel-toe with. With $6,000 you can make an '03 Z4 3.0i beat an M3. In terms of price, you can probably get an '05, BASE Crossfire for $19,000 new, a new limited for $25,000, and an SRT6 for $31,000 (pm me if you want me to find you one at those prices, because I have some significant contacts I can use). A Z4 3.0i, used, is around the price of a new SRT6, probably slightly less. But, you can also get great deals on any '06 BMW Z4, since BMW is offering heavy dealer incentives. I've seen one guy get an '06 Z4 3.0si (255 hp engine), a $46,000 car, for $39,000, new. Just some thoughts to think about. Please ask more if you want anything else answered. Either way they are all great cars, and I myself might get a Z4 M Coupe a few years down the road myself. I've driven it and it's nice!