Quoting turbofonz:
Go to extremepsi.com and buy a new one. I prefer the 2g ones. Old rubber def will do it, if a new dipstick still pops you have other issues, but IMO it's a great idea to buy a new dipstick on any vr-4/1g/2g that still has the original dipstick.
The 2g ones are horrible, the plastic handle always broke over time. The dealers actually replaced the 2g part with the old 1g one. And they are a whopping $15-20 from the dealer. I've also seen people crimp the end of the dipstick tube or slip a piece of hose over the end rather than buy a new one. But, with them being so cheap....
Wiz