I would suggest over building all your surfaces. the front flare doesn't fully intersect the shell. you will need to pull the edges out so it comes complete through the shell if you want to use it as a trimming tool.
transitioning from a t-spline to the nurbs space, and doing further nurbs surfacing tasks is tricky, and there are a number of pitfalls to look out for.
-surface geometry around star points will always be a bit wonky. so you want to place them in areas of low curvature, instead of areas of high curvature like you have here-

creases should be minimized (or eliminated completely) in t-splines, but if your going to use them, never run them through or into a star point-

-avoid anything but 4 sided faces, especially around geometry like wheel wells-

avoid all of the above with better topology. for instance, use edge loops around the wheel wells-

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