What is the third character on this sign seen in Taipei?

Question

I saw this sign in Taipei. What is the third character?

The sign says "不夠_車" - "Not enough ? (vehicle)"

• Is it the character 丩, in which case what does it mean?
• Is it a bopomofo character? - I found ㄐ
• Is it supposed to be an English 4?
• Is the green line at the bottom part of the character or an underscore for some reason?

The shop the sign is on sells scooters / mopeds, or perhaps parts and accessories for them.

Answer 1

What was below the sign? That is, what products did the store sell? It wouldn't be motorcycles?

The sign says: 不够机车, or in old script 不够機車. 機車 means engine, but in Taiwan more specifically motorcycle.

ㄐ + ㄧ in bopomofo is j + i, that is ji, which gives 机.