We currently lease a Mercedes CLK cabriolet and the lease is due for renewal this August. We have been advised that this model is no longer made and that the nearest equivalent is the new AMG Sport E Class cabriolet. We'd like a four-seater convertible. Is this a good replacement or is there anything better on the market? We find the CLK is useless in snow and icy conditions. Would winter tyres make a significant difference?