join the club, had same thing happen and with the broken off piece still in the engine tube you will NOT be able to insert new dipstick but I had a stroke of luck took car to local dealership and they could carry out remedial to the cost of £200, took car to local independant garage,£120 to £150 which I accepted booked car in and few hours later got the call to say car was ready and that they manage to remove the broken bottom part of dipstick by catching hold from the top of the engine, cost £30, now thats what i call a result!!!