You mean Pachira aquatica? I did a lot of research on them when I was given one and found that they are wetland plants that normally grow in swamps. I guess the "aquatica" in their name should be a giveaway. They do like full sun but if yours was behind screens then it would have needed time to adapt to direct sun. The sudden increase in sun intensity, increase in temperature while the car was stationary, and lack of water would have stressed it a lot. Mine is in the ground but I regularly saturate it with water during the dry season. It gets direct sun to about midday and then shade from other trees in the afternoon. I think the problem with yours will be lack of water.

Yes, it's an Pachira Aquatica. It's gotten worse recently. It's been exposed to plenty of light. The screen it was behind didn't impede the sunlight. I replanted it entirely. Any other advice would be appreciated.

Any screen will filter out sunlight to some degree. Just depends on what kind of screen as to how much sun is filtered out. But anyway, full sun isn't really a problem with them. Make sure the soil stays moist and every now and then give it a good flush with water until it runs out the bottom of the pot. Looking at mine now (in the garden) it's putting on a flush of growth since we had a big downpour of rain, the first rain since April. Seems it likes rain better than water from a hose.

Any idea why the tree gives off a funny smell? It's hard to describe. It's like an unpleasant stale, sweet smell. The trunk itself is not soft. It's hard, so I'm thinking it's not from rot, but I don't really know.

I've never noticed any odour from mine but being outside it's be less likely to be noticed. Any chance the smell is coming from the soil?

Post pics.

We're just stabbing in the dark otherwise.

Josh