The split ramps, one for each side I found were pretty dangerous, but the folding ramp where it consists of 4 connected parts that fold out into one large ramp was OK but heavy & cumbersome.
Then you’ve got the problem of the height of the boot opening, it was very tight on my large chair with a C4 Grand Picasso, and there was a bit more head height on the SEAT Alhambra, this is all with the wheelchair seat back folded down & the arm rests lowered.
My current solution is to use my lightweight folding lithium powered wheelchair with the car & only use the larger chair direct from home. It’s easier, I don’t have to hope someone rescues me when a ramp slides sidewards, it’s just safer, and at under 25kg is an easy lift for the smallest of hoists & fits in a pretty small car, my Pug e-2008.