Resistors for Current Limiting

I am trying to install two relays to run my parking lights and trunk switch.  The relays are 30A at 12V, and the fuses at the fuse box for my lights and trunk are 10 and 20 respectively.  Now my question is since the relay is putitng our 30A, I need to step down the current to 10A for my parking lights.  To do so I calculated the resistor i would need as follows. 

Using the equation R = V/I, without a resistor I would get R = 12V / 30A, which is a resistance of .4 ohms.

Stepping down the voltage with the same equation I get R = 12V / 10A, which is a resistance of 1.2 ohms.

Now with my knowledge of resistors, it seems like I would need to add in a resistor of .8 ohms (1.2 - .4 =..8), in order to get the correct current draw.  Can someone help me out and at least confirm that I am on the right track.  It's been a while since my last physics class and I am a little rusty.

There is no need for resistors. Your lights and trunk release will draw no more current through the relays than they do now. The "30A" only means that the relay is capable of passing up to 30 amps of current through it's contacts. It does increase the current draw of your lights or trunk release.

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