Let's see. The fragile jeep has to come to a full stop, then the driver has switch to the gunner's seat, then hope that the tank does not move while the rockets "load"... even if there's a driver in addition to the gunner, it's far from easy to use it as a back-firing anti-tank machine. Making it as slow as Stuka-zu-Fuß won't work, because the 251 hull is protected against small-arms fire and offers some defence against shrapnel. The Jeep will blow up if someone looks at it ugly. Also, the tanker should mind his or her back, because the best defence against Jeep-rocketing is as simple as to back up a few dozen metres and hose the thing with coax MG.
I'd say leave it as is.