it really amaze me how people can actually wait more than a week. Normally if i don't hear within 12 hours, i'd just make a police report.

Please refer to Section 52(2) of the Road Transport Act 1987 (Act 333):

(2) In the case of any such accident as aforesaid the driver of such motor vehicle and, if there is more than one motor vehicle, the driver of each such motor vehicle, shall report the accident at the nearest police station as soon as reasonably practicable and in any case within twenty-four hours of such occurrence, and shall produce to the officer in charge of such police station his driving licence and if so required the certificate of insurance issued under section 90 of this Act.

Section 52(2) of this act shall then be read together with Section 52(5) of the same act which states that:
If any person fails to comply with this section he shall be guilty of an offence

So now you know it's not ridiculous. Likewise in Law, there is this maxim "Delay defeat Equity" - one should not sleep on his rights and procrastinate.

P.s: An eye for an eye will make the world go blind

Haha yeah, actually you may report anytime even more than a week, but after 24 hours, you will be fined as you've committed an offence for reporting late. No one's going to prevent you from making a police report. Minikar is right, if your bumper won't cost a lot, better that you go repair yourself since you'll gonna be paying a fine anw. Also, reporting late is very delicate situation. Hard to prove anything since too long.

Sure. source for which one? The Act? The act is the Road Transport Act as mentioned in the previous post. You may read up.