diff --git a/testdata/dot-ref/car.dot b/testdata/dot-ref/car.dot
index 391d51f..b728077 100644
--- a/testdata/dot-ref/car.dot
+++ b/testdata/dot-ref/car.dot
@@ -7,14 +7,16 @@
 digraph G {
 	edge [fontname="Helvetica",fontsize=10,labelfontname="Helvetica",labelfontsize=10];
 	node [fontname="Helvetica",fontsize=10,shape=plaintext];
+	nodesep=0.25;
+	ranksep=0.5;
 	// Tyre
-	c27 [label=<<table border="0" cellborder="1" cellspacing="0" cellpadding="2" port="p"><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="center" balign="center"> Tyre </td></tr></table></td></tr></table>>, fontname="Helvetica", fontcolor="black", fontsize=10.0];
+	c27 [label=<<table title="Tyre" border="0" cellborder="1" cellspacing="0" cellpadding="2" port="p"><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="center" balign="center"> Tyre </td></tr></table></td></tr></table>>, fontname="Helvetica", fontcolor="black", fontsize=10.0];
 	// Engine
-	c28 [label=<<table border="0" cellborder="1" cellspacing="0" cellpadding="2" port="p"><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="center" balign="center"> Engine </td></tr></table></td></tr></table>>, fontname="Helvetica", fontcolor="black", fontsize=10.0];
+	c28 [label=<<table title="Engine" border="0" cellborder="1" cellspacing="0" cellpadding="2" port="p"><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="center" balign="center"> Engine </td></tr></table></td></tr></table>>, fontname="Helvetica", fontcolor="black", fontsize=10.0];
 	// Body
-	c29 [label=<<table border="0" cellborder="1" cellspacing="0" cellpadding="2" port="p"><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="center" balign="center"> Body </td></tr></table></td></tr></table>>, fontname="Helvetica", fontcolor="black", fontsize=10.0];
+	c29 [label=<<table title="Body" border="0" cellborder="1" cellspacing="0" cellpadding="2" port="p"><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="center" balign="center"> Body </td></tr></table></td></tr></table>>, fontname="Helvetica", fontcolor="black", fontsize=10.0];
 	// Car
-	c30 [label=<<table border="0" cellborder="1" cellspacing="0" cellpadding="2" port="p"><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="center" balign="center"> Car </td></tr></table></td></tr></table>>, fontname="Helvetica", fontcolor="black", fontsize=10.0];
+	c30 [label=<<table title="Car" border="0" cellborder="1" cellspacing="0" cellpadding="2" port="p"><tr><td><table border="0" cellspacing="0" cellpadding="1"><tr><td align="center" balign="center"> Car </td></tr></table></td></tr></table>>, fontname="Helvetica", fontcolor="black", fontsize=10.0];
 	// Car COMPOSED Tyre
 	c30:p -> c27:p [taillabel="1", label="", headlabel="4", fontname="Helvetica", fontcolor="black", fontsize=10.0, color="black", arrowhead=none, arrowtail=diamond];
 	// Car COMPOSED Engine