As suspected, TomTom GPS car kit will work with iPod Touch as well as with 3rd party GPS apps.
According to TomTom public relations manager Yann Lafargue:
It will work with the iPod touch and will also work with third-party GPS applications.
There’s no information on when the TomTom car kit will be available. Although Official Twitter account poster of TomTom confirmed the announcement made at Apple’s Worldwide Developers Conference that it is scheduled to ship “later this summer” with additional specs and pricing coming closer to the kit’s release.
TomTom for iPhone Video: