That all depends.
My truck is a 65 Chevy 3/4 ton 4x4
My other truck is a 72 Chevy 3/4 ton 4x4
So I plan on keeping at least one for some time, especially since the body on the 65 is being re-done.
But, we had a 99 Chevy Lumina as our family car and traded it off for a 01 Impala. The Impala may be traded off this winter, because the extended warranty runs out.
I've worked on cars and trucks all my life, so the last thing I want to do is work on the family car, plus the wife is real picky about the car. Every little noise or miss and she is on me. So if trading the car in on a new one keeps her happy, then that is what I do. LOL!
In fact, the Impala will be in the dealer's Tuesday for transmission work they screwed up, so we may be looking to trade it off alot sooner.