When do i replace the radiator in my 1999 BMW 328i?

If the temperature is normal, you have serviced it regularly, don't have any leaks and the radiator looks to be in good shape on the outside, I see no reason to be replacing it. I've had many radiators last well over 200k without problems. It's not a bad idea to replace old worn items but if you begin changing everything else on your vehicle that's old, where do you stop?