This piece by Zainul Arrifin in the NST seems to indicate that Proton used to have a Japanese managing director back in 1988 – Mr. Kenji Iwabuchi, from Mitsubishi Motor Corp.
The top position went back to a Malaysian in 1993. Datuk Mohd Nadzmi Mohd Salleh. 1988-1993, that’s 5 years.
So a foreigner in the top position at Proton isn’t really as foreign as you think it is.