resistor is basically a 25 Watt power sink that will make the flasher relay think your stock bulbs are still there
hmm after doing some research it seems unclear, advice is 50w and 25w and on all bulbs and on only the rear bulbs !! I did this on my 911 and only did the rear and it worked fine , I'll be doing this on my 370 soon and will update this thread
it was 5 yrs ago I did it on my 350z