Ggplotly: Axis labels overlap tick text

When I create a plot with ggplot, everything looks great. When I use ggplotly to add interactivity to the plot, the axis labels overlap with the tick text. Here's a small example:

df <- mtcars
df$car <- rownames(df)  #intentionally making example with long text
p <- ggplot(data = df, aes(x = car, y = hp)) + 
  geom_bar(stat = "identity") +
  labs(title="Horsepower by car model") +
  xlab("Make and model of car") +
  ylab("Horsepower of car") +
        axis.text.x=element_text(angle=90,vjust = 0.5))

If you simply view p, everything looks fine, but ggplotly(p) results in axis labels that overlap the tick text.
Any suggestions? I've seen similar questions on StackOverflow but no real solutions.

I haven't played around with this much, but you might want to peruse the issues in the plotly repo.

I seem to remember that the developer of plotly reckoned he had about an 80% compatibility to ggplot2, but would need help to bridge the gap further.

Thanks, Mara! I didn't find a solution there but saw some helpful information for other issues.