Interference: Conclusion

This filter business probably seems like a lot of work and bother. But you may not even need it! If you want to use LED lights/flashers, install them first, and test them with the engine off and on. More than likely, if you have a stock setup, they will work fine.

Only if you are having interference problems, most likely from aftermarket circuitry or ignitions you might have added, do you need to consider the filter circuit described. In that case, it is something of a bother, but the good news is, at least it works.