Most modern cars are just getting heavier, more limp wristed engines and cheaper build quality. I know there are exceptions but how many new cars do see and you think "I want to take that round the nurburg ring?"
I see plenty of superb cars, Stu! There aren't many old cars I'd fancy taking round the 'ring, with their brakes fading... New cars are better, no question. More power, greater economy, better handling, far, far safer, modern kit, more reliable... The only issue may be styling, which is a question of personal taste, but in every other aspect, a new car wins. Are you really telling me you'd prefer a 164 to a 166? Or prefer to keep your 166 over a new, RWD 169? No way!
I kind of see some sense in this.
1. You want to reduce the miles and wear on the 166.
2. The 145 may well be a relative bargain.
It never adds up, though. You reduce the mileage on your 166 (so what, if you're keeping it?) but it costs you the purchase of another car, another insurance policy, a second lot of VED, another MoT, various repairs & maintenance etc. Total economic madness.