We recently purchased the FenSens Smart Wireless Parking Sensor for our car. This device is awesome. It took less than 5 minutes to install. It has no wires, and includes a hands-free App (Android/iOS) that launches instantly. It provides convenient audio, visual, and vibration alerts, indicating objects in front of or behind your vehicle.
On a recent trip to New York City we used this device and it helped greatly with parking in Manhattan. The phone app guided us through the entire process. For someone that is not good with parallel parking this made it a cinch.
The FenSens Smart Wireless Parking Sensor is an easy way to update your car's technology. I give this product a thumbs up and recommend buying one.