Welcome in Mr new guy.
a moving vehicle is going to be tricky. Slot cars, unless they have changed in the many long decades since I have messed with them, have integral motors and gears ( motors and gears built into the frame. this makes it hard to do any modifications, If there are commercial mods available, whey will be for more speed, and not less.
With trains, the motors are separate, and can be replaced with gear head motors to get very slow smooth operation.
One possibility might be making a horse powered trolley, which looked much like early electric trolleys, except for the horse in front Bachman makes a lot of stuff in On30 ( O scale narrow gauge 30 inches between the rails) This uses the same gauge (distance between the rails) as Ho gauge standard gauge, but in O scale ( 1/4 inch to the foot I think). I'm thinking most of the Christmas village stuff approximates O scale.
The early On30 enthusiasts used HO scale mechanisms, now Bachman makes lots of stuff, greatly expanding what is possible in O scale narrow gauge. I recommend looking at this stuff, the detail is awesome, and it may end up looking much better than the lionel.
Good luck, look around here, not enough traffic at this site, but there is a lot of good projects going on here and much to learn.
Bill Nelson