help with capacitor

I 've been working on getting a old directional bar. Old style bulbs, LED's.Thread is Converting Light Bar, by dcsbass.( https://www.electro-tech-online.com/threads/converting-a-light-bar.90631/#post714028) Have Worked out resistors with you all help and especially Mr Sceadwian. But it was suggest to add a capacitor! A small one, maybe 10u electrolytic, just to buffer the power a little and suck up small surges! To buffer the power from noise and mute short voltage spikes. It is an auto (DC V). So I can keep going or you can read my other thread.
Please Help

Thank You

10u may be a bit much, I tend to use 10u for everything =\ You can use smaller ones, someone here should be able to recommend the best cap to use, all it really needs to do is absorb any transients that occur, cars are pretty noisy and prone to short voltage spikes.

Help with a capacitor

Mr Sceadwian, I don't think I'm going to get any help.
Thanks

I checked a few random circuits made for cars on the net, none of them seem to use caps on the VCC lines, why I'm not sure but, maybe a .1u just on general principals.