Well i couldn't resist having a little peep before i went to bed last night. Big Mistake! I finally managed to tear myself away at 4am and am suffering greatly today...
Anyway, here's my thoughts so far..
It's necessary to point out that is is a pre-alpha build and as such it's pretty ragged round the edges. People have reported input lag (although i didn't have any) and graphic glitches (a few minor glitches in DX11 for me). There's all sorts of stuff which isn't implemented/doesn't work/looks funny so you have to look past all this stuff. With over a year of development left things will change a lot but SMS need to be applauded for giving access to such early code. Brave stuff indeed.

Right, onto the important bit....
Graphics Quite simply the finest looking driving game i've ever seen. It's absolutely stunning, anyone wondering what Shift 3 might have looked like then this is your answer. I'm sure you've all seen the screenshots and yes it looks that good. Of particular interest is the lighting system which is mind blowing. I've never considered myself a graphics whore when it come to racing games but when things look this good you can't help but be drawn into an extra level of immersion which makes the driving experience that bit more visceral. It does come at a price though but if you could run Shift 2 then you should be OK here.
SoundThose who know a little of SMS's history will no doubt go warm and fuzzy at the inclusion of Stephen Baysted's GTR2 anthem as the title track and it serves as a nice reminder that the company hasn't forgotten it's roots during the EA wilderness years. Apart from this there's not really much else happening until you hit the track. Once in the game, engine sounds are amazingly meaty and incredibly detailed. They growl, pop, rasp and sing louder than a dragon with his balls on fire. Almost to the point where i found myself thinking it was too much at times. You're left in no doubt that you're driving a race car! Once again it's hard not to be impressed by how much this adds to the driving excitement. Skids, sequels and scrubbing are all present and those who have played the shift series will know the kind of audio visual assault to expect but it sometimes feels a little much for a 'serious' sim.
ControlsSome users have reported problems with input lag, over saturation etc. I didn't notice any of that. My equipment consists of four separate controllers (wheel, pedals, shifter, button box). In many sims this can be a nightmare to configure but C.A.R.S accurately detected all of them right away. I only had to map a couple of keys and i was ready to go. This really surprised me as I had no end of controller problems in Shift 1&2. Other people have reported strange behaviour in the FF department but it was nothing short of spectacular for me - in fact i'd go out on a limb and say it's even better than iRacing in that respect. I could feel every bump, force and even individual tyres losing traction. I had no input lag and felt connected to the track at all times. The wheel somehow just felt 'right' from the get go. Saturation, deadzone, linearity, worldmovement etc can all be tweaked so there's no shortage of settings to get things feeling how you like. Seat position and FOV can be adjusted in game which is a welcome touch. Cameras consist of the usual hood, cockpit and swingman. Replays are not properly implemented although you do get a slightly ropey playback of any major impact.
UICurrently it's pretty simple in an rfactor kind of way and i hope it stays like that. Load the game, 2 clicks and you're on track in 10 secs. There's a wealth of options and almost everything is tweakable from the main menu. The simplistic clean nature makes it feel like a piece of software that wants to be taken seriously. Great stuff. I know this is one area where the devs want to make some changes but i really hope they don't complicate things with over the top shift like presentation.
PhysicsI find myself in a real dilemma here. As it stands at the moment this is no 'hardcore' sim but that doesn't mean it isn't great. My first thought when i hit the track was 'All these cars have too much grip' and you really can chuck them around. It's definitely a world apart from the shift games though and things are tightened up a LOT. However those people expecting the cars to bite you like they do in some rf mods will be disappointed. As i did more laps and pushed the envelope some interesting things started to happen. The handling is very progressive so as you get faster you can feel the car starting to get away from you and there are lots of warning signs that something bad is about to happen, this makes it possible to catch minor slides and make corrections that would otherwise catch you out. Overstep the mark however and you WILL end up facing backwards or in the wall. Driving the Lotus 68 with this kind of behaviour reminded of GPL on more than one occasion which can only be a good thing. Damage modelling is implemented but not terribly intricate at the moment.
The more laps i did the more i started to really like how this works. It gives you the scope to hustle the car but becomes a real challenge to keep on the edge. I still hold with my initial judgement that the grip levels are too high but it's a very interesting (and addictive) dynamic that kept me playing well into the small hours. In fact despite the cars feeling quite 'safe' I ended up in the wall more times than i care to remember. I didn't encounter any unexpected behaviour - suspension, tyres, aero etc. all feel good although not outstanding. Overall i kept thinking the handling felt reminiscent of Race07 (with a bit more grip and a slightly 'woolier' feel). One other thing i noticed was that corner entry sometimes felt a bit vague but it was 3am. I'm guessing those people used to console/semi-sim racers will think the handling is a real step up. The hardcore simmers will probably remain undecided but still enjoy the experience.
Of course there are no setup options yet so it's possible that a lot of this is down to conservative defaults but it definitely feels like there is scope for another difficulty level above the 'pro' option.
OverallDespite a few gripes i can't deny that i'm having a heap of fun with this, graphically it's untouchable. Sonically it's undeniably impressive but possibly sometimes for the wrong reasons. There's definitely some real potential in the physics department but it needs refinement. I'd say it currently feels like SMS have put things where they always wanted them for the Shift series. In no way is it an arcade racer but it sits right on the fence. Which side it falls is entirely in the hands of the community and which direction they decide to push. I'm just hoping that the simmers shout louder than the console crowd as there is undeniable potential here. Will it turn into an IR/rF2 killer? or just Shift 3 by another name? It has the potential to do either but regardless of the outcome, the project is completely open to modders and what this alpha build illustrates more than anything is that C.A.R.S is an unquestionably powerful platform that drags racing firmly into the next generation.
Evidently there's a long, long way to go but it's a captivating project and definitely worth an investment to get your hands on the regular builds. C.A.R.S has a real spark under the hood and if you can live with the bugs then even the content contained in the pre-alpha is worth the entry fee IMO.
And any project that has the Stig on the dev team gets my vote!

(and no, i'm not kidding!)