Here are some thoughts from my experience.
When we first started out, I bought some 8-foot long suitcase ramps that fold down to 4 feet long. I used these to load the wheelchair into the back of an SUV. To do so, the wheelchair back had to be almost completely reclined. This worked, but was so impractical that I only did it twice; once to test load the chair and once to transport the chair to try it out on a used van that we bought.
The instructions for the ramps included a dire warning that I could not ride in the wheelchair while it was on the ramp.
I have kept the ramps as an emergency backup in case our wheelchair van is out of service and I just have to get the wheelchair somewhere. In the beginning, I could have stood beside the ramps and used the joystick to drive the wheelchair up the ramps. I can no longer do that, so it would require someone else to do it.
I still don't need to ride in the wheelchair. I can comfortably transfer to the front seat of our wheelchair van. We purchased a van that would allow us to transport the wheelchair, but in which it would be impractical for me to ride in the wheelchair.
We have a full-sized Chevy Express 1500 conversion van (with a raised roof) with a Braun Vangater II wheelchair lift and EZLock to lock the wheelchair in place in the mid section of the van. There is a shoulder harness there, but when it comes time for me to ride in the wheelchair we will replace the van with something I can see out of as we drive.
If you get a minivan, be aware of the cargo and passenger carrying limitations (both weight and volume). Also be aware of their low ground clearance (low enough to be a problem with speed bumps).
Here are some recommendations:
1. Get something where you can ride the wheelchair into the van
2. Get something where the wheelchair rides in the van (not on a platform attached to the back of the vehicle). Wheelchairs are very sensitive to weather.
3. If you get something where you cannot ride in the wheelchair, recognize it is a temporary solution. You will eventually need to ride in the wheelchair (either in your van or be relegated to using public transportation).
4. Get something practical to use. If it is hard at all, you will find excuses not to use it.
5. Be sure you can safely lock the wheelchair in place. I am a fan of systems like the EZLock. While I have used straps, we find them cumbersome.
6. Unless you have the finances or aid to support paying the high prices of new, buy used.
We bought used and I found that good vans went very quickly. I looked on craigslist, autotrader, etc. I found our van on craigslist. We paid cash and had the money ready to go so we could beat other buyers to the deal.
If you buy from a private party, keep in mind they are selling it for a reason. I had not anticipated this (though, I should have). They had recently lost their disabled son.
I had never envisioned owning a van. Now that we have ours, it has really grown on me. We have plenty of space to haul stuff. We have spent a lot of time thinking about what our next vehicle will be. We initially were sure it would be a converted pickup.
After lots of investigation, we are now pretty sure it will be a Mercedes Sprinter or Ford Transit van with a wheelchair lift and the passenger side seat removed. That would give us plenty of volume and weight capacity for hauling people and cargo. I could sit in my wheelchair in the front passenger location and see out of the van. There would be minimal modifications to the van (install a lift, remove the front passenger seat, and install an EZlock). The fewer modifications, the less to go wrong.
Steve