A great way to deter theives is to install a flashing LED. Once they see a red flashing LED, the thought of an alarm will deter most theives. What is needed is the LED to flash when the car is not running. This is to ensure that there is no annoying LED flashing while you drive. The materials are 1 flashing LED, one 150 ohm resistor and one grommet (for the LED mount). Honda's come prewired for almost everything. The clock is prewired even if is not being used. Above the fan controls is the central venting unit with a clock unit. This venting unit can be removed with the help of a screwdriver. On the reverse side you will find a connector for the clock. Remove this connect and there should be 4 wires. The black wire is ground. Look for two wires: A-One that is hot all the time (note that this is also Option terminal #5, the far left terminal), and B-One that is hot when the ignition at "ACC" (note that this is also Option terminal #3, the far right terminal).
Connect the positive end of the LED (with 150 ohm resistor in series) to wire A and negative side to wire B. Check that the LED flashes when the ignition is off and stops flashing when the key is turned (ignition on). What you have is a professional looking alarm system. To make it more authentic, get some alarm stickers from Car Audio Store, preferably Clifford once. This mod may also apply to the other generations of Civics as long as there is a clock wire that is hot when then ignition is on. The LED could be placed anywhere on the dash or even the center console.
Nevertheless, a real alarm is the best option. Thieves usually check if the alarm is real by hitting the car and seeing if a warning chirp comes on/alarm goes off.
