no, its very easy to install them using saat, just find the sounds you want to replace and then import the new sounds.
you can apply thse sounds to any car you like, you just have to find whare each sound is, heres a guid for the sound banks;
http://www.gtaforums.com/index.php?showtopic=296844
i made the sounds by recording them from videos from the web with a program called audicity, it is quite hard to make them work, and you often get crackly rubbish sounds with some of them.
The first sounds i recorded were from the fd rx7 that han drives in tokyo drift, but they didnt work out so good as their was always music playing in the background.
so i got some for any modified fd rx-7
this is whare the mod is;
http://www.gtagarage.com/mods/show.php?id=10753
its not uploaded yet because it needs to be checked and stuff but it shouldnt take to long
hope you like it :]