[Closed] First car ... 100miles a day ... 1 years use ... Bangernomics?

Use the nice new car.

Especially if its only for a year.

You've been over-thinking the downsides a bit IMO.

Motorbike.

Take the family car when it rains.

Apart from the run what you've got, to back up the MX5 argument, my wife was doing a 100 mile round trip daily. Decent lights and wipers (as with anything really) and it was fine. 35-40mpg with my wife driving (and not entirely stock). Over a year, you would probably sell it for what you buy it for. Work eventually let my wife have a van and allowed her to work from home after a van rear ended the MX5 on a slip road.