I love my new BMW, but YES, I do find it embarassing that it dosn't speak streetnames! So should the BMW engineers!
I'm a software engineer. I tinkered with synthesized speech on the Apple II and TI-99/4a back in the 1980s! If I had the code to the BMW system, it would take me less than a day to integrate a TTS engine and have it speaking street names, at least in most western languages. There are free open-source options available, or for a few dollars per car they could license a nice-sounding commercial offering. The pronunciation on those things is highly variable, but it doesn't matter. We kinda like to laugh at how our Garmin Nuvi pronounces Hawaiian street names when we travel there. It's also weird that BMW has speech recognition (which is "hard" to implement) but no text-to-speech for street names (which is very "easy" to implement).
Saying "turn in 300 feet" is what the bad early nav systems did back in 1998. Speaking street names is a must-have feature for a $150 consumer nav unit -- not to mention Google Android Navigation and VZNavigator on hundreds of phone models. It should be in a ~$2000 nav system on an ~$80k car.
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As for dead-reckoning. I agree standalone GPS units can sometimes have positioning troubles, though I've never seen them in my Garmin Nuvi, only the older Magellens. My Verizon Droid3 (and my droid-1, blackberry, and LG Chocolate before it), all use cellular assisted GPS, which has been perfect as far as I've ever seen. The only downside is that these systems only work with cellular reception, which means, ohh, just about everywhere. Maybe some cut-outs in tunnels and remote areas. In my experience, consumer systems (especially Google Android Navigation) currently blow away car systems by a wide margin.
Though I suppose it all depends what you consider "good". I consider it good if it's easy to enter an address, get a decent route, and follow the directions. As a bonus, it's nice if it has traffic info, alternate routes, and lets you route around a problem, searching for stuff is a bonus, but I generally do that on my mobile device not the car. (I would **LOVE** an Android Google Maps send-to-bmw feature, but alas that does not currently exist)
My post didn't include all the positive and negative aspects of either system, as it wasn't intended to be a complete review. Here is a more complete list of the differences between the 2010 lexus 450h nav and 2012 BMW idrive nav
Lexus 450h nav vs bmw idrive, this is how,
in my opinion, the two stack up in
core navigation features:
- both have decent traffic info/display
- both have POI display, nearby major streetnames (but never the ones you want)
- both have available operator-assisted stuff (BMW Assist, Safety Connect)
- both have voice systems with marginal recognition quality (because speech recognition is "hard")
- bmw allows you to enter an address while leaving city the same, lexus requires you to re-enter city each time
- bmw allows you to operate while driving, while lexus does not
- lexus speaks all streetnames, bmw does not
- lexus funny mouse-controller is easier to use, requires less driver attention than idrive (ironic that lexus won't let you operate while driving)
...and here is a comparison of their
nice to have features:
- bmw has the ability to manually route-around a specific route section, lexus does not
- bmw has better (more specific) options for voice prompts, allowing you to enter or correct a part of an entry without full-reentry
- bmw has nice visual hud integration (if you have the HUD)
- bmw can warn of out-of-gas and suggest gas stops, lexus leaves that to the driver
- bmw allows you to google-search for a POI, lexus does not
- lexus has a nicer "temporary overlay" for radio/climate changes, while bmw's overlay must be toggled manually
- lexus nav map seems to require less 'fiddling', during navigation it shows the right amount of nearby context... returning to this auto-mode after fiddling requires just tapping the map button. On bmw you have to scroll the zoom level to the left until it hits auto, and even then I don't find the context shown as appropriate as lexus