Finally bought this hose reel at AMK Hub NTUC. For S$29.90, it comprises of 1 reel, 20metres hose, nozzle and connector to tap. The hose is too long for my car wash. I may have to trim it shorter for ease of use at the washing bay. Have yet to find the time to test it out noting that fact that the washing bay is using timed water dispenser. Here's the picture of what i have now.

Hmm.. wonder if i can connect to a 12 volt water pump and a water storage tank.