How do you know I'm not pulling 1.6Gs of acceleration? Oh right, Miata. :v
Given that I'm using $10 in cell phone software and an $80 GPS, I really don't expect the data to be fantastic. As far as I'm concerned, the only data that can really be used reliably is lap times and speeds. Everything else is probably garbage.
I like the Nexus 4, and I've had no complaints about it. The lack of external storage and battery access is a negative point; however, that's about the only negative point about it. AT&T's HSPA+ is decent and I was pulling a bar or two at CMP.
e: I used this case just suction cupped to the dash
http://www.amazon.com/gp/product/B007FH ... UTF8&psc=1 It didn't move all weekend and the phone didn't move at all. I just velcro'd the GPS to the top of the windshield.