With all of the features we want and none of the duplicates, Pioneer's AVH-4100NEX is the simplest, most cost-effective option for drivers who just want to add Android Auto or Apple CarPlay to their ride.
Android Auto is Google's new system for integrating Android phones with car dashboards, unveiled at its I/O 2014 keynote.
The Audiovox Car Connection's main benefit is letting parents keep track of their children's driving behavior for a relatively low per-month price.
The Plantronics K100 delivers great-sounding, hands-free calling on both ends of the line, and its FM transmitter is a nice bonus when it works, but look elsewhere if your phone is one of the few that don't support voice-activated dialing.
The Pioneer AppRadio 3 is significantly improved over the previous generation and one of the best choices for drivers wanting safe access to smartphone apps while on the road.
The Pioneer DEH-X9500BHS packs in a remarkably wide range of audio sources for a single-DIN receiver, including some rudimentary app integration.
The Zubie Connected Car Service keeps good track of the family car and can help people be better drivers, but the lack of fuel economy information is a big miss.
With a built-in navigation system and a decent range of media playback options, the Kenwood DNX7100 cannot be faulted for its breadth of features, but the system is let down by its counterintuitive media-selection interface.
The Aukey Portable Bluetooth Receiver comes with more features than many similar products and a clever means of remotely controlling playback from your phone, but it will involve running wires to a power outlet and an auxiliary input in a car.
The CarMD Vehicle Health System turns up very limited data compared with the cost of the device, and it offers few real features.
For iPhone 4 and 4S lovers, the Pioneer AppRadio 2 is possibly the best aftermarket receiver that money can buy. For Android users, the choice isn't so obvious.
Even though it's definitely not one of the more effective FM transmitters we've tested, we liked the AirPlay's minimalist design and decent sound quality.
The Sony XAV-W1 is a stylish new entrant into the aftermarket in-car audiovisual market. Its SACD-playback ability will interest serious audiophiles, while its stunning display and intuitive media-selection interface will attract anyone looking for a user-friendly in-car media player.
With its fast response times, easy-to-use navigation and audio, and support for Apple CarPlay and Android Audio, Sync 3 is a huge boost for Ford cars.
Carloudy, a new head-up display Kickstarter project, shows turn-by-turn navigation and speed limits in easy view on your windshield.
If you want easily accessible emergency services and like the idea of having a real person on tap to help you pick destinations, OnStar FMV may be worth a look.
Voyomotive comes up with a device adding connected features and advanced engine control to almost any 2008-and-after model year car.
The Grooveshark Bluetooth Car Kit isn't the best hands-free calling option and its app integration needs finessing, but the hardware is an easy way to bring Internet radio and smartphone audio playback to almost any car.