Nice gallery. I think I've commented on the Porche and the maybach before, so I'll just focus on the rest this time.
The VW Citi feels very natural. Looks like what the VW design studios would come up with. The conservative style is perfect VW.
The Benz CLH on the other hand looks very unbenz like. Maybe its the execution of the detailing or the lack of the three pointed star, but I would not know the design was for a Benz.
The CLK vision surface concept uses the S-class tail light design in a more elegant fashion. But the side surfacing is very distraction. Maybe tonned down a bit. Seems that there is some perspective issues with the rear wheel also.
The subaru impreza bodywork is just fabulous. It looks agressive without looking too boy racer. A very mature and cohesive design.
The Honda Integra, is simply beautiful literary. This design is what simplicity should strive for. No excessive distrating details here, just harmonious integration of simple shapes and form. An evolution of the current civic Si front end but with more deserved aggression. excellent. My favorite in this gallery.
The VW Typhoon looks somewhat at odds with what is expected of a supercar. The golf front end is overbearing and ungainly while the slender rear is lacking in some seriously needed supercar details. Maybe a sketch from another angle would be more appealing.
The jaguar XJ is beautiful and so is the render. Like the quad round lights. The uncanny resemblance to the XF is not bad either.
I like the aggressive headlights and the wavy waistline of the Audi A7. The design looks good, but it needs some refining to make it perfect. The perspective of the rear wheel and the top line of the windshield needs to be adjusted a bit. otherwise cool sketch.
Now the lexus convertible is the best execution of the complex surfacing you were trying to achieve with the Benz CLK concept. It is better suited to the desing theme you used in the Lexus. It is a very good design. For some reason, it does appear just as bloated as the current SC, so a reworking of the proportions might help bring it to closer to Maserati or aston martin perfection.