Q. I bought some new suits before Pesach but I didn't get a chance to have them checked for Shaatnez before the beginning of Sefirah. Can I use them now or do I have to wait till after Lag Baomer. Also I have the same question about a car bought before pesach, but the delivery got delay until before Lag Baomer. Also clothing bought on sale during the beginning of Sefirah, do I have to wait until after Lag Baomer to use it?
A. There are different opinions and Minhogim in regards to using new clothing during the days of Sefirah, some forbid (Leket Yosher O.C. p.97) some permit (see Nitey Gavriel - Pesach 3, ch. 54,3).Horav Shlomo Miller's Shlit"a opinion is to be lenient.
The ones that prohibit do so mainly because of the brocho of Sheheyanu, that they consider improper at the time of sorrow of Sefirah. But they permit wearing them on Shabbos or on Lag Baomer, since the brocho is recited at the time we wear them first. Non important clothing is permitted in need (Afrakso Deaniyo 176).
Buying a new car is permitted also if required, (Nitey Gavriel ibid. 55,6) as the minhag applies mainly to clothing.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit"a