Automatic Transmission Cooler?

I wouldn’t have thought it necessary as you shouldn’t be putting a huge load on the gearbox with your light van. However, I know nothing about Suzukis. 

What sort of auto box is it? Torque converter, CVT, dual clutch…..

Torque converter

In that case, I stand by my first statement above 👍🏻

I suspect that transmission coolers are only added when you have experienced a problem rather than in anticipation? The car should be able to operate within the towing weights given by the manufacturer. I once fitted an additional cooler to a Vauxhall Charlton because the gearbox fluid used to boil whilst towing. It didn't help much but eventually Vauxhall came up with a simple remedy to cure the problem, all that was needed as an expansion chamber! 

David

I'd be surprised if it didn't already have some kind of cooler ... either air to oil across the front of the car somewhere or water to oil built into the main radiator. All my slushbox autos have had.