kinshuk,
1) I've had one bad experience on my safari with plugs/ strings . after a few month, the expansion and contraction of tyre (due to heat or vibrations ) will introduce small leaks around the plug.
also, if you hit a stone or other reasonably sharp object around the plug, it may come undone and cause sudden loss of pressure (catastrophe ).
for Me, one bad experience is too many, as my beast hits north of 160 on many trips and safety First.
2) if you visit surat deathway you'll know what I'm talking about. at the 2 railway crossings, fools have made... err.. mountains that even small trucks may scrape on. we have to take vehicle at an angle to get over them. one thing is sure that xuv lacks ground clearance compared to safari or fortuner.