If you're looking to run a mobile rig in your Jeep, the basic license will cover everything you need.
If you want to get into mobile HF (longer wavelengths and ability to talk over longer distances), then the Basic (plus) qualification will probably cover everything you need. You get that by scoring over 80% on the exam - not too hard to do if you apply yourself to studying.
Advanced would only be needed if you want to build your own gear, or run big amplifiers - neither of those things is all that practical to do in a Jeep. Myself and most of the guys that I've seen with rigs in their Jeeps seem to run VHF/UHF rigs. With the repeater coverage that exists in Souther Alberta, VHF can do a lot.
If you want, give me a call. IThere's a lot of ground to cover, and every question that gets answered leads into another question