about the gap, afaik, the production will have the filler wire/metal to coverup the gap. But better check it when receive the car. It shud be there. About water sipping, it wont rust cost all metal is galvanised metal n there are lots of holes around any car. If not,all will be rusted easily, but still insist checked whether the filler wire is there or not.
About turbine unit from borg wagner, not only vw, audi,n skoda used it, ford ecoboost n volvo also using the same turbine.
It used water-cooled bearing casing n can stand high temperature up to 1050 celcius.
This question also will raise up, why use timing belt? Then the answer given to me both systems, chain or belt have pros n cons. If not, why vw also opt for belting, n ford ecoboost also using the same thing. It just we always exposed to japan n korean techs, we left the part on europe techs. Cozz campro based engine is develop by lotus, n the design of course based on what they familiarise before, europe based. Thats why coolant used by campro based engine is the same type u found in the contis,rather than the japs. Remind u, taking care of coolant is really important for conti based engine, dont simply add up water.
And punch cvt using metal belting rather then rubber belt as in some others, thats why rubberband effect is not appear. The lag is not rubberband effect. Just google for further understanding.
Im a layman, so, cfe,iafm+ n cvt is not the most state of the art tech in the world, but not either outdated one. Just for example, iafm+ already comes with new generation 32 bit ecu easy-u from continantalag/siemens vdo, while ford 1.6 duratech ti vct only used 16 bit application, that that ford engine is the current one. Not saying iafm+ is better than ford duratech ti vct, it just that iafm+ is not as outdated as people might think. Using punch cvt does help a lot on catering the wieght of preve compare to flx se, thats why century sprint is not that far from flx se. If use mitsu auto, then it will be a big gap.
Have u heard the word gear ratio can immitate torque? Being having infinite ratio give cvt advantages compare to manual@auto gbox. The ratio is really wide, so that it will choose suitable ratio accordingly to the weight. While in conv at, the engineers have to test every ratio n choose the best n balance one with power n fc, while cvt, just mapping n the cvt will adapt iself. Thats why it has its own tcu n adaptive function.
U can take a look at manual preve sprint time, its the same as cvt based flx se. But manual based flx se sprint better than manual preve. Maybe can ask dares to check up the owners manual book since he owned flx se cvt. It supposed to be there.
That is my layman explaination. Cant explain further coz not engineer, just convey the word from friends.