The Kela 2 only came in Standard and Tall which, together with your lowered van, is most probably why you had the untidy, flappy sides and tunnel. The Kela 3, as well as being a step up in quality, comes in a Low size, which is designed specifically for VW size campers.
We have also purchased the footprint which we are hoping will assist with lining up to the van.
Another tip our converter gave us is to roll the Fiamma awning out slightly before attaching the figure of 8 and then roll it back in to apply a bit of tension to the drive away awning once everything is pegged out. Hopefully, together with the lower design, this will get around the problem you describe of the figure of 8 walking and fabric getting trapped in the slider.
We really do need the extra outside space, especially when sailing (which is a big part of our camping) for storing and drying all the extra kit we carry such as wetsuits/drysuits. For weekends and overnighters without the boat we will probably leave the awning at home.
Since we've had the awning we have made a point of speaking to people we have encountered during our summer camps using the Kela 3 with Transporters - everyone we have spoken to really likes it and would recommend it. Also, one of our friends has just traded up from a Vango Sapira to a Kela 3 for use with their Bay and loves it (so much so that when their Bay developed a serious engine problem last week they seriously considered going away using their family car and the awning for a pre booked family trip this week).
I'll put some more comments and photos up once we have used the awning for real, hopefully in about 4 weeks