The coil in each relay should draw around 100-200mA (check the specs for yours) so you should be ok running 5-10 of them off of your cigarette lighter circuit. As mentioned the fuse to the switch is redundant because the cigarette lighter circuit is already fused. Also, you show a ground connection for the switch which I'm assuming is because it is illuminated, otherwise the switch doesn't need to be grounded.

If you are using the switches to control exterior lights then I agree with Steve that you shouldn't run the high current wires into the passenger compartment. Instead I'd recommend putting a fuse or circuit breaker on your +12v line as close to the battery as possible, and then mounting your relays in the engine bay and using the fused +12v line to power your relays' pin 30. You would then wire your loads to pin 87 (you can actually reverse this if it makes the wiring cleaner since the relay is just a switch).

On the control side you would ground all of the relay's pin 85 as you show, and then wire up pin each 86 to the output from one of your switches. One option is to get a ~18g multi-conductor cable, such as sprinkler control cable, and run that from the switch panel in the passenger compartment to the relay box in your engine bay. Make sure you use stranded wire because solid wire can fatigue and break under vibrations like you find in a car.

On my 4Runner I ran a wire off the positive battery terminal directly into a fuse block which powers a few relays. I use an 8 conductor cable to run the control power from the switches in the passenger compartment.



- Matt