Add following manually in shoppings.dat file:
To section prices - section CarMods:
		bnt_a_cl		CLBBRS		respect 0 	sexy 0		600
		fbmp_a_cl		CLBAFF		respect 0 	sexy 0		990
		fbmp_c_cl		CLBCFF		respect 0 	sexy 0		990
		rbmp_a_cl		CLBARF		respect 0 	sexy 0		990
		rbmp_c_cl		CLBCRF   	respect 0 	sexy 0		990
		rf_a_cl			CLBARV		respect 0 	sexy 0		190
		rf_c_cl			CLBCRV		respect 0 	sexy 0		150
		spl_a_cl_b  		CLBASP		respect 0 	sexy 0		900
		spl_b_cl_b  		CLBBSP		respect 0 	sexy 0		600
		spl_c_cl_b  		CLBCSP		respect 0 	sexy 0		700
		spl_d_cl_b  		CLBDSP		respect 0 	sexy 0		400

To section shops - section carmod1 (to make them appear in the mod shops):
		item bnt_a_cl
		item fbmp_a_cl
		item fbmp_c_cl
		item rbmp_a_cl
		item rbmp_c_cl
		item rf_a_cl
		item rf_c_cl
		item spl_a_cl_b
		item spl_b_cl_b
		item spl_c_cl_b
		item spl_d_cl_b

Add following in gta.dat file:
IDE DATA\MAPS\veh_mods\clubparts.ide

If you want to use the parts, replace string starting with club with this:
club, bnt_a_cl, fbmp_a_cl, fbmp_c_cl, nto_b_l, nto_b_s, nto_b_tw, rbmp_a_cl, rbmp_c_cl, rf_a_cl, rf_c_cl, spl_a_cl_b, spl_b_cl_b, spl_c_cl_b, spl_d_cl_b