Oh and:

100 OHM adds about 1-2 watts of load
15-25 OHM adds about 6-10 watts of load
6 OHM adds about 25 watts of load
3 OHM adds about 50 watts of load

3 OHM resistors on each side (2 total) or 6 OHM resistors at each bulb location (4 total) should work fine for us.