我怎样才能精确地塑造它？

Question

我正在尝试画一辆汽车作为我的参考。但进展非常困难。我没有得到正确的想法和解决方案。这是我的参考车。

\documentclass{article}
\usepackage{tikz}
\usepackage{pst-plot}
\usepackage{pst-eucl}
\usepackage{amsthm}


\usepackage{environ}
\makeatletter
\newsavebox{\measure@tikzpicture}
\NewEnviron{scaletikzpicturetowidth}[1]{%
  \def\tikz@width{#1}%
  \def\tikzscale{1}\begin{lrbox}{\measure@tikzpicture}%
  \BODY
  \end{lrbox}%
  \pgfmathparse{#1/\wd\measure@tikzpicture}%
  \edef\tikzscale{\pgfmathresult}%
  \BODY
}
\makeatother

\makeatletter
\newcommand*\setupscalewithtikz[1][\linewidth]{%
\newsavebox{\box@tikzpicture}
\newlength{\newwidth}
\setlength{\newwidth}{#1} 
}
\NewEnviron{tikzpicture*}[1][]{%
  \begin{lrbox}{\box@tikzpicture}%
  \begin{tikzpicture}[#1]
     \BODY
  \end{tikzpicture}% 
  \end{lrbox}%
  \pgfmathsetmacro\width@scale@picture{\newwidth/\wd\box@tikzpicture}%
  \begin{tikzpicture}[#1,scale=\width@scale@picture]
    \BODY
  \end{tikzpicture}% 
}%
\makeatother

\begin{document}
  \begin{figure}
      %\centering
      \begin{center}
      \begin{scaletikzpicturetowidth}{.8\textwidth}
          \begin{tikzpicture}[scale=\tikzscale, declare function={
              excitation(\t,\w) = sin(\t*\w);
              noise = rnd - 0.5;
              source(\t) = excitation(\t,20) + noise;
              filter(\t) = 1 - abs(sin(mod(\t, 50)));
              speech(\t) = 1 + source(\t)*filter(\t);
            }]
            \draw
            [draw=black,rounded corners=6ex,very thick] (3.6,0.5) -- (1.5,.5) -- ++(0,2.5)-- ++(3,0);% --  ++(15,0) -- ++(0,-2.5)--++(-2.5,0);
            \draw[draw=black,rounded corners=5ex,very thick](14.1,3) -- (16.1,3) -- ++(0,-2.5) -- ++(-2.1,0);

            \draw[draw=black,rounded corners=1.2ex,very thick](6,0.5)--(11.6,0.5);

            \draw[very thick, rounded corners=5ex,thick]  (4.5,3) -- ++(2,2) -- ++(6.6,0) -- ++(1,-2);


            \draw [draw=black,very thick](6,.5) arc (0:180:12mm);
            \draw [draw=black,very thick](14,.5) arc (0:180:12mm);


        \end{tikzpicture}
        \end{scaletikzpicturetowidth}
      \end{center}

      \caption{Sensitivity analysis for cut Model of car}
      \label{fig:sens_1ncar}
  \end{figure}
\end{document}