Did they make a difference on your motor?
Indeed its very tight in there, but I like them nice and tight
I've not been out in the dark yet, but even in the daylight they are brighter than the stock. I just swapped one to start with so I could compare them. Colour of the light seems very similar too.
The only other problem was getting the bloody things out of the bloody packing. Almost as tight as the access in the car
EDIT:- Just tried them in the dark (albeit not actually driving) and they light output is great. I think you could use them to signal the Martians