I've been using temic parts for six months now. The have an office about 20 miles from me, so that obviously helps. They have been really helpful in terms of selecting parts, and they have a good range of micros. I think that this will be the third time I have mentioned their U5021M watchdog chip on this forum, but it saved me _loads_ of board space - and a reasonable amount of money too.
They also do a large number of automotive control IC's too, which may be of interest to Richard Houghton, if you're reading this thread, judging by 'What you have done'