If you have a Ferrari or a Mercedes with CarPlay on your shopping list, we have some good news. iOS 7.1 with CarPlay support has just been released.For the rest of us, it looks like the usual selection of tweaks, bug fixes and enhancements, with a bit of an update to the interface too. CarPlay is perhaps the most significant change here though, bringing iOS to four wheels, as long as those wheels are (initially) from Ferrari, Mercedes or Volvo. So access to your phone, music, maps, messages and some third-party apps, with control via the interface or using Siri.But it's not all about car owners, features have been updated across the board. Siri has seen some love and now has a manual control for speaking (rather than leaving it to Siri to guess), along with 'more natural sounding' male and female voices.iTunes Radio has an improved search function, plus there's the option to buy music while it's playing and easy access to iTunes Match, should you want to subscribe and kick the ads into touch. The Calendar gets a monthly view for displaying events, with country-specific holidays also added and accessibility is improved with bolder fonts, a Reduce Motion option and new options to display button shapes and darken app colours.Finally, rounding up the bits and piece, you can now enable HDR automatically on the iPhone 5s, FaceTime call notifications are automatically cleared when you answer a call on another device, the home screen crashig is a thing of the past, Touch ID fingerprint recognition is improved, performance should be better for the iPhone 4 and the interface has been 'refined'.Got all that? Good. It's available now if you want it, but is quite a hefty download, as well as a long update process. So make sure you are in a Wi-Fi area with time on your side before you even think about it.