Puxing PX-777 plus

The PX-777+ arrived today. $AUD 83 including shipping from HK. It took five days to arrive which is not too bad for 'including shipping.' KB2SRH has a good youtube of it here.
Came with a free earpiece mike thingamy. Great! This will hack nicely into the OT+.
The manual is the typical Chinese translated into English by someone who only speaks Lithuanian. Fortunately I only need to program one simplex frequency into it. And I learned AngloCinoLithuanian during my service in the Foreign Legion.
The quality is what you would expect for an 83 dollar transceiver... the battery doesn't quite sit snuggly against the radio. The charger doesn't work when the radio is inserted. It works if the battery is inserted by itself. That's not going to work too well for an unattended APRS setup.
The antenna is an SMA but the opposite gender to, say, a Yaesu VX-3. In other words you can screw the PX-777 antenna into a VX-3 antenna. This also means that the tiny and fragile SMA pin is in the radio, just waiting to be bent or broken. The pin should be in the antenna. If you break the pin, you throw the antenna away. I bought an SMA to BNC adaptor a couple of days ago so that will sort that out. Loctite will sort it out even more.
Need to sort out an antenna. I'm using a mag base with a modified ¼ wave so it will almost fit under the car port. There's a twang as it hits a support beam. Also, it seems that I'm not making it into any digipeaters for half my journey to work using 5 watts. I might have to look and a 3db (or better) antenna which definitely won't fit under the car port. This means another antenna up the back of the car.
I'm considering doing away with the PX-777 LiPo battery altogether and running it from the car power via a voltage regulator. 7.4v will probably mean an LM317 or similar. The OT+ and GPS can run from 7.4v as well. That could save a lot of messy wiring.
I'm also considering breaking out the RS232 signal from the GPS to plug into a laptop or car PC. This would allow me to log trips. OpenStreetMap is very sparse in my locality. There's also the option to run nav software. I have everything I need to make a low power car PC, except for a display. I need a VGA LCD that can run from 12v that doesn't require funding from selling my first born.