How to CFrame Lerp a model?

I have some code, which makes a object follow a path of parts. This is for a rollercoaster. I was wondering if anyone would able to help me so that:

1. It moves a model instead of one part
2. Anyway to make it more efficient
3. Is there anyway to get all the track parts without having to manually write every one

Thanks!

local p1 = script.Parent:WaitForChild("Track1")
local p2 = script.Parent:WaitForChild("Track2")
local p3 = script.Parent:WaitForChild("Track3")
local p4 = script.Parent:WaitForChild("Track4")
local p5 = script.Parent:WaitForChild("Track5")
local rp = script.Parent.CarFront


while wait() do
    for i = 0,1,.05 do 
        rp.CFrame = p1.CFrame:lerp(p2.CFrame,i)
        wait(0.0001)
    end
    for i = 0,1,.05 do 
        rp.CFrame = p2.CFrame:lerp(p3.CFrame,i)
        wait(0.0001)
    end
    for i = 0,1,.05 do 
        rp.CFrame = p3.CFrame:lerp(p4.CFrame,i)
        wait(0.0001)
    end
    for i = 0,1,.05 do 
        rp.CFrame = p4.CFrame:lerp(p5.CFrame,i)
        wait(0.0001)
    end
    for i = 0,1,.05 do 
        rp.CFrame = p5.CFrame:lerp(p1.CFrame,i)
        wait(0.0001)
    end
end