Is it hard to install a sound system on a 2008 honda civic sedan?

i have a 2008 honda civic with navi, since technology has been changing, is it really hard now to add some sub-woofers to my stock navi?Is it hard to install a sound system on a 2008 honda civic sedan?Best Buy can install anything in anything.Is it hard to install a sound system on a 2008 honda civic sedan?not very hard . you will need to replace the alternator if over 500 watts .. honda is a car that there is always something comming out for..