Hey There!
I actually just pulled the trigger on a similar setup. Kiwi was really expensive compared to many other successful readers that are already out there.
On Monday i bought an ELM327 bluetooth reader off of ebay for $18 these have been used far and wide so I am hoping for good results. I couldnt find any tests on this platform however.
Anyways They make a wifi version for idevices. From everything I read they are pretty lag free. I will know in a few days and will report back. Also IMHO ipads look really stupid in our cars. I went with a Nexus 7 as it is hires, quad core, fast bluetooth and it sits perfectly flush in our top cubby hole.
http://www.ebay.com/itm/290812437816...84.m1423.l2649