I understand your situation, but, how long till your insurance goes down, Another year?????
you will prob still loose value on the lex even tho it's just sitting,
Will the Pug not be worth selling?, can you pay lump sums off against your loan?
Obviously you will have more spare cash if using the pug, but if you cannot close out the loan early then there is no point in your plan.
Maybe you should have saved, then bought the car instead of finance, i know it's too late but keep it in mind for the next change of car, buy what you can afford, or else it's a slippery slope.