Instruction: Answer the given question by extracting information from the supporting document.

Input:
Question: Does this unit require separate speakers or can you hear the unit on the bike while riding? Easily swappable from bike to car?
Document: I received my 665 and spent a few hours doing a very neat installation on my bike. I got the XM working easily, just like it had withmy 376C this was replacing. I was excited to have the phone capabilities. My iPhone 4S paired right up, but when I place a call I can hear the person on the other end, but they couldn't hear me. I called Garmin support and held for quite some time and then got someone to help me.
So, making adjustments while riding is very difficult.In general, the hardware of the unit is very good. I love how easily it works with no buttons. But, the software could use some fixes. Basecamp is absolutely ridiculous. Whoever made the decision to switch from MapSource made a mistake IMO.
Which means if you don't permanently mount the antenna, you will want to remove both the GPS unit (easy) and the antenna (annoying) each time you leave your bike unattended6. You're paying 3 times as much for the bike unit as you would for a car one. Granted, it is weatherproof and bike friendly, but it is still a price premium over say getting a car GPS and a waterproof tank case
This was a gift for my husband. He rides and needed an easy to use GPS.He likes the versatility of moving it from bike to car.
i wanted somthing that play music it does that. i read where it could not be seen in bright sun light i had no problems.i also like that it can go from bike to car. the only outer thing i woud of liked is tempature but i guess yuo can't have every thing
It's a compromise GPS in a lot of ways, and far more expensive than a strictly car one. But if you have both a car and a bike, this is as good as it gets. My husband has the Garmin Nuvi in his car and comparing that to the Zumo, there are a few features I miss.The pros:1. Weatherproof2. Bike oriented settings  - usable with a glove on, big buttons3. Easy on/off bike mount4. Lifetime map updates5.
This is significantly more advanced than my older Zumo 550, units that are not specifically designed for bikes fail quickly due to vibration and elements so it is worth spending a bit more. The features on the 660 make it very useful for the rider, distance to destination, speed limit, easy navigation and enhanced graphics for turn by turn guidance. Don't buy the separate wire kit because the package includes everything to use in an auto or to be mounted and wired to your bike.
This unit does allow my Sena headset (a popular motorcycle bluetooth headset which fits in a motorcycle helmet) to pair with the GPS and then allows me to hear the instructions.First, let me say, I really like this GPS and I am glad that I got it.
Again a very poor design. It's a hard wired unit so power consumption shouldn't be a concern but it seems that Garmin is clueless about this issue. The screen glare and lack of brightness adjustment is abysmal. Hey Garmin...did any one with REAL world riding skills ever test this unit?
With all of the external distractions, bigger, easier to read screen is King.Looking forward to using this unit in the upcoming riding season, my Zumo 550 will continue to do duty in my various vehicles or where ever else it is needed. The Zumo has endured what no piece of electronic equipment should be exposed to and the 660LM should preform just a well.
Answer: You will NOT be able to hear the speakers build into the unit. I have the Cardo Scala Rider Bluetooth in my helmet. In the car you can connect the AUX mini stereo plug out to the car's AUX input quite easily.