The fact that you're in a wheel chair means you spend most of your life in the same position the rest of us are in when driving. Strong side belt holsters are not easy to access when seated. The most easily accessed is a shoulder rig, but it requires the use of a jacket to conceal it. A belt mounted cross draw holster would still be easily accessed, but wouldn't be as visible. In fact, you could probably get away without any cover garment as it would be tucked between your off side hip and the chair.
As long as we're talking about this, let me ask a different question. Why are you looking at a compact handgun? You don't have to walk with it and the chair can help you conceal it nicely. I'd say, get the biggest damn gun you can find and get a good quality cross draw holster.