Reception issues

I have a 89 civic dx hatch and i just installed a new system but the reception is horrible. what's the best way to improve this and about how much do you think it would cost? and is it an easy install?

okay i'ma break down am and fm reception in a nutshell. Fm frequencies are picked up by your antenna. This will be the only cause for shitty reception on the fm side. The slightest break in the wire from the actual antenna to the motorola plug that goes into the back of your radio. This has only one exception and that is if the tuner inside the radio is going which will happen from time to time. Alot of ppl even in the industry think that am reception comes through the antenna which isn't true. The chassis of the car is used as an antenna. That's why cars made before fm that have radios don't have antennas. Check out your home stereo the fm antenna is usually two wires that spread apart to recieve more signal but the am antenna is usually just a plastic loop with wire in it. This loop just makes a ground plane to recieve signal.