Places to stop between Shinjuku-Hakone?

My family of five will be going to Hakone from Shinjuku using a rented car. Are there any interesting places during our trip that we can stop by?

Thank you in advanced!

Famous spot between Hakone from Shinjuku
Nihon Minka-en of Mukogaoka-yuen, Fujiko F Fujio Museum (reservations required).
http://english.nihonminkaen.jp/
http://www.japan-guide.com/e/e3252.html
Yomiuri Land
http://www.gotokyo.org/en/kanko/inagi/spot/s_674.html
If you come in July or August, sunflower field of Zama is also famous.
If March from the second half of February, ShinMatsuda Kawazuzakura and Seto yashiki of Hina ningyo(dolls), plum of Soga is also famous.
Odawara Castle is under construction until the end of April of next year.