Grid Width in polar.plot

Hello,
I am using the polar.plot function from plotrix.
Is there a way to change the width of the grid lines?
grid.lwd doesn't work....

Hi Martin,
At the moment, there is no option for changing the width of the grid 
lines. However, I have had a statistically significant cluster of 
requests for various features like this in different functions of the 
plotrix package and am considering a major rewrite of many of the 
functions in plotrix. If the idea I have turns out to be successful and 
I can actually find the time to do the reprogramming, it will solve most 
of these "feature" problems without bloating the functions with too many 
arguments or making the specification of the arguments too difficult for 
the average user. Keep your eyes open for an announcement.

Jim