just keep the reflective band around your tire sidewalls relatively clean
head and taillights with a 180 degree angle of view should be adequate..
It is for me anyhow..
a simple Retrofit is Reelights
http://www.reelight.com/
..the magnet is on the spokes..
Basic model, a light, white faces forward, red faces back
is attached to the axle ,, the LED blips on every time the magnet induces a current in the light ..
http://shop.reelight.com/bicycle-lights/12-sl100-set/
there is a coil of wire in there .. the electricity by induction principle.
get 2 magnets per wheel means 2 pulses per rotation.