Mobility Scooters/chairs

Need some advice. I have been using my rollator and mobility car up til now but i can't get the rollator in the back easily.I was talking to an elderly gentlemen on his mobility scooter. He said it made a huge difference especially going up and down hills where the rollator goes without me and I am having to hang on for grim death.My question is for those who have mobility cars. Is it possible to swap your car mid contract to a more mobile friendly vehicle. When I first got it 18 months ago i was still walking, Now I can't walk without help and dread going into towm 1 mile away . I don't want to give up my car yet even though I only drive a matter of yards now and make sure I don't hold anyone up. I can't cope with a dog rollator hills and slopes.I keep falling over when something gets in the way. I have to look for flat kerbs as I haven't the strength anymore to lift the rollator over kerbs and have to wait for someone nice to come along.So much for being independent. I lurch and furniture walk around the house>you know how this disease is progressive-a fact that others don't understand.