LJ_24, don't get my intentions wrong, but from your posts I assume that you are not personally involved in the poduction of those LED's. I guess that you are just selling them. My strange questions come from the fact that I've been dealing with LEDs for a long time and I want you to make a good product and I want mudders to be happy. Here is some info.
Most products with SMD LED's have three LED's in series and a resistor inline with them. This just won't cut it in the long time. Current spikes in cars will kill them within a year. Here is the example of a wrong setup for three leds:
(batt plus)---LED---LED---LED---RESISTOR---(gnd)
A slightly better option is to connect one resistor per LED. As a result (I won't go into calculations here) a voltage spike has much lower impact on LED's. The risk of damage is like 5-8 times lower. Example for connecting three LEDs:
(batt plus)---LED---RESISTOR---(gnd)
(batt plus)---LED---RESISTOR---(gnd)
(batt plus)---LED---RESISTOR---(gnd)
A much better solution (but still cheap, the part costs 30 cents) is to put a current regulator like LM7812. One regulator per lamp will be enough as it has a limit of 1.5A so even a cluster of 70 SMD LEDs won't be too much. With one of these current regulators you can even connect the LEDs as in the first scenario and they will live a happy life. No example below as it will be too hard to draw with fonts, but you get the idea: first the regulator and then you take plus and gnd from it and connect the LEDs. I've been using this setup for 5 years in my truck and not a single LED has failed.
The best solution is to use a dedicated current sensing circuit but it will ramp up the price to a few dollars per piece. Not necessary for this application IMHO.
Are you aware of all this? I don't want a dissappointing product here on Mud

. In case you need more info, just let me know.
p.s.- the current limitin resistor your supplier talks about does not protect against reverse polarity. You would need at least a diode for that.