The solutions always gets you on the interest. With a car like the GTD/GTI having such a high guaranteed future value you will always be paying interest on a large proportion of the car's cost, unlike a bank loan where the proportion of your monthly payment going towards interest really wanes after years 1 and 2.
If you're going to keep this car for 5 years or more then a personal loan makes more sense - the whole car paid off in 5 years, opposed to the solutions route where you might pay a bit less each month but at the end of year 3 you've only paid off 45% of the car (the depreciation). Solutions if you change every 3 years, bank loan if you plan on keeping it 5 years.
I'm going to be made redundant in either Sept/Oct 2014 or June 2015, but i'll come out of it with about £50k redundancy

At the moment i'm used to paying £410 a month for my Roc. Part of me is erring towards taking out a 2 year solutions deal so i'm still paying a high amount (with £5k down) and pay the GFV off with my lumper, or do I leave it at 3 years, only paying about £270 a month, and then pay off the car as soon as I get my lumper? 2 years Solutions will cost me less interest at a steeper repayment rate.