possibly - the n810 has different dimensions. but I don't know why you'd do that, because is has a perfectly good built-in GPS receiver! All you need is the car mount amd power adaptor - isn't the car mount included with the 810?

As for the OP's original question - I'm very happy with a Holux M1200. Very sensitive (it even works indoors, to a certain extent), nice and small, good battery capacity, can lock on while moving (not all GPS receivers will do that). It locked when I turned it on in a 747 at 30000 feet. Oh, and it was cheap too.

The build-in GPS of the N810 sucks. A Sirf III (also in TomTom) is much better. But yes, car mount is included. Perhaps only a Sirf III does the job.

I don't think it's a universal conclusion that the gps of the N810 sucks. I don't have one, I don't know. But someone just a few posts ago said that most gps's were similar and that it doesn't matter much which gps you get unless you are looking for specific features. That seems to me to imply that the gps of the N810 doesn't suck.

Certainly the many comparison threads for the N810 and the N800 that I have seen didn't have "the gps for the N810 sucks" as an agreed-upon item.

The problem with N810's GPS is that it takes ages to lock. Once it has a lock, it works well. Sirf III doesn't have this problem. This is generally accepted, and its why I'm searching for an alternative. If enable my GPS system I want to use it right away. I don't mind to wait 3, 5 or 10 seconds but anything over 30 is simply too much.

Unfortunately it's not true that most gps'es are similar, at least not yet. (In the not-too-far future this may become true though.)

There are different chipsets out there, and the N810 version is some TI chipset, which main feature is low battery drain. At the moment I'm aware of only 2 really good chipsets, that's the already mentioned Sirf star III, and also the MTK chipset. Both are used in different new Holux GPS'es, and I think the Sirf one is used in the freedom keychain GPS mentioned in another posting.. in fact most if not all of those GPS receivers recommended in earlier posts in this thread use one or the other of these two chipsets.

(Be aware that there's also an earlier Sirf star II chipset out there, which is vastly inferior to the III version).

Got the Sirf 3 BT device. Instant lock, even inside the house with no direct line of sight. It is almost impossible to get a lock inside the house with the internal GPS, and outside it takes long, if I ever get one at all. Sunday I'm gonna test it out more, driving around. Thus far I'm very impressed though (and more sad about the internal GPS which has been almost useless for me thus far).

I have a Mio C220 which has a SiRFstarIII and sometime it takes for ever to lock in / pick up satellites. Other time it's quick. All in the same general area. (LA, California) Worked from May 2007 till about a month ago, now has a fatal error which can't be fixed without sending back to Mio along with $100 .

I also have a N800. For simple car use along with points of interest which software for N800 would be best to use with the gps. I use the points of interest a lot. ( Mio has 3.5 million POI. )