Only for the Chinese market is the designation changed.
This has to do with the sound of some numbers, which thereby resemble other words.
The number six "liu" is pronounced with a falling tone and sounds so similar to the word for "liquid" (liu with rising tone) which is good for business. Six symbolizes happiness.
In Chinese the number four as "si" pronounced with a falling tone. This is similar to the word death, also "si" but with a falling and then rising tone.
Especially in informal conversations, these words sound the same.
Eight is "ba" and sounds similar to the word for prosperity and wealth "fa". An eight looks like the symbol for infinity, and a node which represents a successful union.
It also appears that the word "168" sounds like "the path to prosperity."
The 164 actually says: With me you'll luckely kill yourself...
The change the '4' into an '8', this became: With me you'll drive to happiness, prosperity and wealth.

Like all non-European models there was a 168, a 168L and 168S, with the only difference: the nameplate.
It was later released with a 168 Super V6 24v engine and a 6-speed automatic gearbox.

 More about the 168 in our Library