Never underestimate the the internet's ability to solve problems.
Yesterday, I received my new iPhone 4, and quickly found out that the TomTom iPhone car kit does not recognize the phone at all: no GPS fix, no "Docked" recognition, nothing. So, I Googled around, and found a few people having the same issue: the iPhone 4 simply doesn't work with the car kit. The consensus when I went to bed last night was that TomTom would have to release a software fix.
But when I woke up, I checked again: someone had figured out the problem and a workaround: stick something behind the base of the iPhone so the connector hits the port at the right angle. So, I tried it, and it totally worked.
I did some testing, and was able to find a pretty good minimum thickness: 0.07 inches, 1.778 mm, or seven 10pt/80lb business cards.
