With the Technician license your limited to transmitting on 6m and above. I mostly only use 2m in the truck and car. I have a dual bander with 440, but I just never put it in the vehicles. I am a general class license so I can use HF. When I travel I will install a rig in the truck that covers 1. 6Mhz - 440Mhz.
As for antenna locations, I used to have one mounted on the front corner of the bed. It worked great but when I got my pickup camper it had to go. Now I mount it on the hood on the Drivers side. I have an MFJ mount that clips onto the inside edge of the hood with set screws.
For 2m I use a diamond antenna, for HF I have one made by Yeasu that will adjust itself up and down as required for the band I am on. (only covers 7Mhz on up)
I here there is a change in the works where Technician licenses will be allowed to transmit in the HF bands, once that happens you will have a lot more decision's to make about which radio you want.
I have a yeasu FT-847 for base use, a Yeasu Dual band for the car (I never seem to use) a Yeasu HT and a Kenwood 2m mobile that is in my car. Guess I can say I really like Yeasu stuff as well