break/tail light bar

Hi, hopeing you can help me with advice on resistors for the following- 

i going to have a go at building a light bar similar to the one in the link (if it works) and useing the leds (also in a link)

my question is what resistors will i need to get the leds to turn brighter when breaks are apply'd, i've just done a repair on one the same as in the link for a fellow hilux owner and forgot to check the colour bands on the risistors in it, (it's all sealed up now and cant check) they seem to be wired (on a thin circuit board) in groups of four with a risistor each, (one leds had failed and the track near it had split, so it knock'd out four leds on this bar), how do i wire them to get this dual brightness, i dont want to buy this ready make one after looking at the build quality plus i want to use more leds than this one has, not sure how many yet till i find a suitable houseing for them, thanks for any help,

ian