Thanks for the replies chaps, pleased to hear that I will fit in the i40.
Yes I would really love to keep the Lexus but it only returns 17 mpg around town and I just don't do the miles that I used to.
The Lexus is a fantastic car but will need some cosmetic work doing to it and even an LPG conversion and respray will set me back around 5k, which I cant really justify spending on a 17 year old car with negligible resale value, so a more economical car is the way forward for me and the i40 ticks all my boxes so long as I keep away from the model with the panoramic roof (thanks for that tip!).