Personally, I think the userbar as is, looks amazing. However, if you want to extend it width wise, likeSenpai suggested, you could make the overall size of the userbar (the original one) smaller, and lengthen the red side bars. Therefore you keep the center the original shape, without stretching the userbar and distorting it.
Just a suggestion
I think I agree, I'll try making it a bit thinner in that case