Yes. Only 1 of the stages can be installed at a time. Installing both stage 1 & 2 at the same time is redundant.
Preve failed to meet my expectations. Not that I'm expecting much, but I like PE more than Preve, interior-wise. The Preve feels like a new gen Turtle Extreme with its raised dashboard & shit. There are, however, some nice touch to it like red light at the compartment below air cond controls. I hate to say this, but Proton made good use of the Preve's interior space by providing ample amount of storage compartments everywhere, unlike the Persona which had a rather tiny glovebox and armrest compartment.
The boot lid is light and it feels tinny, sort of like an old Iswara's boot. The lightness is fine or may even be useful for the ladies, but the cheapness of the material used can be felt when you slam the boot shut. Not so good for a 'global car' (my ass) image. Gone are the days of solid, heavy boot lids on Wajas & Personas that closes with a 'thud'.
The bootspace is fine, but look rather awkward to me. If you guys realise, in all the latest Proton cars, the boot is designed to be high rather than wide and long. Starting with the Waja, the boot is increasing in height/depth, up to the Persona & now the Preve. If this trend goes on, I'm sure we'll see a day where Proton make only vans.
Back to the interior. Material used on the dash seems refined, which is good. Love the feel of the top dashboard, but not so much on the dashboard, centre console & door trims. Honestly speaking, the door trim on the Waja feels better. There really is nothing much special about the car, apart from the Engine Start button and the digital display in the middle of the meter cluster, which I find rather cool.
Now, the engine. Cold start gives an uneven idling, RPM hops around 750-950 RPM. Honestly speaking, the insulation isn't as good as reviewed on Paultan.org. Disappointing, because with the doors shut tight, there's a clear engine whine that penetrates into the cabin. I don't remember my PE's engine to be that noisy new, or even now. I only get to start the engine for the showroom car, didn't get to test drive it as the media guys took the test drive unit out. But honestly, after the walkaround & through the car, I'm not interested to test it either. Not a big fan of the CVT, so I won't bother reviewing it as well.
All in all, Proton has improved in a few areas that they should (standardised ABS, all-round disc brakes, airbags), but cut cost in places that they really shouldn't (firewall insulation, bootlid, and TYRES. Galah Tunggal Champiro) for the Preve. If I have to, I'd rate it 6 out of 10. It's still far from being good, and the abundance of
teh tarik hooks in the car doesn't change that very fact.
I wonder if the media is paid to say good things about the Preve..

thanks for the review..
decison made....
wait for better version..