Why Lauterbrunnen and not Wengen? Park your car at Lauterbrunnen in the big garage at the station and then take the train up to Wengen and find a hotel. Waking up in Wengen to that amazing view and then the train up to Jungfraujoch are very special experiences.
You'd possibly need 3 hours to get to Liechtenstein given there is usually a fair amount of traffic at a few points along the way. Unless you just want to cross the border and turn around. That you could do in a shorter time.