DPP HDR tool - picture

I have just discovered the HDR tool in Canon's camera software, Digital Photo Professional. I've never done HDR, so I thought I'd give it a go. First shot below is a manual blend of 2 shots, first one spot metered off the buildings, second one spot metered off the sky. Second shot is the HDR using the same 2 images. I like the detail recovered in the tree on the right, and the way the highlights have been toned down in the central building, but I don't like how the car's light trail has lost its centre. Is there any way around this (apart from what I did, which was composite it back in using layer masks in GIMP)?

Manual exposure blend of 2 shots.

HDR image using same 2 shots as above. Note the unwanted detail through the centre of the car's light trail.