Weaker yen spells trouble for Detroit.

Discusses the strengthening of the US dollar against the Japanese yen and its implications to the automobile market of both countries. Advantages enjoyed by US automakers during the higher rate of yen since 1990; Possible comeback of Japanese automakers to the market making it more competitive; Rivalry between the General Motors Corp., Ford Motor Corp. and Chrysler Corp. of US and the Toyota Motor Corp. of Japan.