PCA with ellipsis without colour in R

I'm trying to make a PCA plot for publication. That means without colours. However, all packages I have tried color the plot in the moment that you tell it to group the categories of the data.

I have already tried the packages: ggbiplot, ggfortify and factoextra. Unfortunaly, with no success.

On code that I have tried (from here):

library(ggbiplot)
mtcars.pca <- prcomp(mtcars[,c(1:7,10,11)], center = TRUE,scale. = TRUE)

ggbiplot(mtcars.pca)

ggbiplot(mtcars.pca, labels=rownames(mtcars))

mtcars.country <- c(rep("Japan", 3), rep("US",4), rep("Europe", 7),rep("US",3), "Europe", rep("Japan", 3), rep("US",4), rep("Europe", 3), "US", rep("Europe", 3))

ggbiplot(mtcars.pca,ellipse=TRUE,  labels=rownames(mtcars), groups=mtcars.country)

And return This image

But I what I need is something: like this

Hope I was clear enough.

Solution

The answer of @SantiagoCapobianco has all of the pieces but does not put them together.

Using dataEllipse from the car package goes all of the way with the right arguments.

library(car)

mtcars.country <- factor(mtcars.country)

dataEllipse(mtcars.pca$x[,1], mtcars.pca$x[,2], mtcars.country, 
    levels=0.8, xlim=c(-5,5), ylim=c(-4,4), center.pch=0,
    col=rep("black", 3), pch=15:17)
legend("topleft", legend=levels(mtcars.country), pch=15:17, bty='n')