Interior Detailing...Dashboard/Vinyl Protectant or No Protectant?

[STC]

Next month I will be cleaning and detailing the interior of my new Yaris. After cleaning the windows, dusting, and vacuuming, I would like to protect my dash and doors from cracking and preserve from premature aging and dullness with a good protecting conditioner.

I have heard vinyl conditioners can actually lead to dashboard cracking, if not applied regularly after the first application? The protectant will bring out the shine, but if you do not condition all the time afterwards the dashboard will dry out from the protectant’s chemical solution because of the sun’s harsh rays and the car’s extreme interior heat. Thus crack? I was told this years ago, when I lived down South. Is this the true? Or is this just a wives’ tale?

Has anyone just used a product one time and had no issues afterwards? If so, what brand?

What should I do? I now live in a temperate climate zone in the North East.

Thanks...