I can share my personal experience. When I made up my mind to purchase car kit AUX Link, I compared all the prices and it's really cheaper to purchase it at the official online store
AUX Car Kits. The adapter was delivered in just five days. At first I decided to try to install it on my own, but experienced some problems extracting the car stereo. I didn't have the right tools, so finally I had it installed in the nearest autotuning workshop. It took just 10 minutes. So far I'm totally contented with the purchase.
Advantages:
- compatible with Apple devices, USB flash drive, SD, and there is also a 3.5 mm mini audio jack for other mobile devices (MP3 players, Android and Windows smartphones, tablets, laptops, netbooks, PSP and so on).
- crystal clear sound
- can be used as a charger
- with optional Bluetooth dongle can be used as a Bluetooth car kit
- music control with buttons on the steering wheel and buttons on the car stereo (very convenient)
- supports all music formats
- free and fast delivery
- occupies very little space and almost invisible
- now I can enjoy all my favourite songs without carrying piles of CDs.
Minuses:
- a bit expensive as I also ordered additional Bluetooth module to use the adapter as a handsfree car kit
- couldn't easily extract the car radio so I had to go to service center
But taking everything into account, I believe it's a good price-quality ratio. So from my point of view it's worth buying.