There seems to be a lot of 12 month deals around at the moment but this is the first I've seen for a car like this. S2000 2.0 GT Convertible for £299 a month + VAT from smartlease.co.uk. I suspect the deposit will be 3 months (£897 + VAT) then 11 payments at £299.
You wouldn't get this on a 3-year deal at that price.
The new Porsche Cayman is now available so I thought I'd see what is around. New models usually hold up well on residuals and this one is no different. This means that rentals start at around £599 per month plus VAT on a 3 year deal (3+35). (www.skyfleet.co.uk)
Best get your order in now as these are likely to have long wait for delivery.
If your on a tight budget then a £99+VAT lease deal is about as low as you an go. The selection of cars in this category isn't great but as an example hr-cars.com have a Citroen C1 Vibe at this price based on 3+23, 10k miles per annum.
If you try hard enough you could even find a deal at £99 including VAT. Good luck!