Games in the car

We used to have a van with a built-in dvd player, ahh the good old days. These days we have to think of other ideas to entertain ourselves (besides poking each other).  Yesterday my second son (13) and I played bet you don't know how to say this word in malay. Yes its lots of fun for us. I learned a little malay from a book and tape before we went to Malaysia in 2000 and also knew some random words dh would use sometimes with the kids plus some kind malay sisters taught me a bit over the internet plus I learned quite a bit in the 4 months I stayed in Malaysia including my handy dandy dictionaries. My son also learned a bit in some of these ways including his recent trip to Malaysia for 5 weeks. So it was quite funny to stump each other.  A lot of our knowledge overlaps but he didn' t know the word for shoe (kasut) or for ear or nose or dishes, lol. He stumped me with tomorrow, wood, the days of the week and watch ( I guessed waktu but that's time). Can your kids speak their father tongue? What ways do you use to learn the language of the fatherland?