There are apps for Android that read the iTunes data on your computer, so if your iPhone is synced to your computer, you should be able to just sync to your Android. (Don't know about the car - there are too many Bluetooth variations to keep track of ll of them.)
Make CERTAIN that you drop your phone from iMessage before switching over, or anyone with an iPhone iMessaging you will be sending texts to a dead phone. It's a hassle doing it after you switched the account to another phone.
http://phandroid.com/2014/04/07/turn-off-imessage-iphone-to-android/ And if their messages still don't get to your S5, tell each of them to send you at least one TEXT message. iMessage (on their phones) will pick that up and keep the information stored, so when they forget and iMessage you it'll still go as an SMS.
One thing you should be aware of. In an iPhone, there''s normally one way to do things (sometimes as many as 2 ways), so you just do it that way. With Android, any developer is free to write any app he wants, so there are 25 ways to do exactly the same thing and 200 apps to do it with. You have to make decisions. A lot of owning an Android phone is downloading apps to see which one you like best. They all do the same thing, but that button is in an inconvenient place for the way you hold your phone, so ... If you don't like constantly making decisions, Android isn't for you. But if you want the phone set up your way, doing what you want, the way you want, an iPhone isn't for you.
One of Apple's old sales lines was "the computer for the rest of us" - I translate that as "the computer for the lemmings". They carried that philosophy over to iStuff. There's so much more you can do with an Android. But if you don't want to be doing anything but using the camera app for pictures, the dialer app for making calls, iMessage for messaging, etc., iPhone is the phone for you. A lot of people coming from iPhones complain that there are too many choices. So I hope you like choices.